Inductive CL_core: Type :=
  | CL_State
      (f: function)
      (s: statement)
      (k: cont)
      (e: env)
      (le: temp_env): CL_core
  | CL_Callstate
      (fd: fundef)
      (args: list val)
      (k: cont): CL_core
  | CL_Returnstate
      (res: val)
      (k: cont): CL_core.Inductive CL_core: Type :=
  | CL_State
      (f: function)
      (s: statement)
      (k: cont)
      (e: env)
      (le: temp_env): CL_core
  | CL_Callstate
      (fd: fundef)
      (args: list val)
      (k: cont): CL_core
  | CL_Returnstate
      (res: val)
      (k: cont): CL_core.Inductive CL_core: Type :=
  | CL_State
      (f: function)
      (s: statement)
      (k: cont)
      (e: env)
      (le: temp_env): CL_core
  | CL_Callstate
      (fd: fundef)
      (args: list val)
      (k: cont): CL_core
  | CL_Returnstate
      (res: val)
      (k: cont): CL_core.Inductive CL_core: Type :=
  | CL_State
      (f: function)
      (s: statement)
      (k: cont)
      (e: env)
      (le: temp_env): CL_core
  | CL_Callstate
      (fd: fundef)
      (args: list val)
      (k: cont): CL_core
  | CL_Returnstate
      (res: val)
      (k: cont): CL_core.Definition CL_at_external (c: CL_core) : option (external_function * signature * list val) :=
  match c with
  | CL_State _ _ _ _ _ => None
  | CL_Callstate fd args k => match fd with
                                  Internal f => None
                                | External ef targs tres => Some (ef, ef_sig ef, args)
                              end
  | CL_Returnstate v k => None
 end.Definition CL_after_external (rv: option val) (c: CL_core) : option CL_core :=
  match c with
     CL_Callstate fd vargs k =>
        match fd with
          Internal _ => None
        | External ef tps tp =>
            match rv with
              Some v => Some(CL_Returnstate v k)
            | None  => Some(CL_Returnstate Vundef k)
            end
        end
   | _ => None
  end.(*Previously we had this: but afterEtxernal clause in ChmgenproofEFF (MATCH)
  requires to have Returnstates
Definition CL_after_external (rv: option val) (c: CL_core) : option CL_core :=
  match c with
     CL_Callstate fd vargs (Clight.Kcall optid f e lenv k) =>
        match fd with
          Internal _ => None
        | External ef tps tp =>
            match rv, optid with
              Some v, _ => Some(CL_State f Sskip k e (set_opttemp optid v lenv))
            |   None, None    => Some(CL_State f Sskip k e lenv)
            | _ , _ => None
            end
        end
   | _ => None
  end.
*)
(*
Definition CL_after_external (vret: option val) (c: CL_core) : option CL_core :=
  match c with
    CL_Callstate fd args k =>
         match fd with
            Internal f => None
          | External ef targs tres => match vret with
                             None => Some (CL_Returnstate Vundef k)
                           | Some v => Some (CL_Returnstate v k)
                           end
         end
  | _ => None
  end.
*)
Definition CL_halted (q : CL_core): option val :=
    match q with
       CL_Returnstate v Kstop => Some v
     | _ => None
    end.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.Inductive clight_corestep: CL_core -> mem-> CL_core -> mem -> Prop :=

  | clight_corestep_assign:   forall f a1 a2 k e le m loc ofs v2 v m',
      eval_lvalue ge e le m a1 loc ofs ->
      eval_expr ge e le m a2 v2 ->
      sem_cast v2 (typeof a2) (typeof a1) = Some v ->
      assign_loc (typeof a1) m loc ofs v m' ->
      clight_corestep (CL_State f (Sassign a1 a2) k e le) m
        (CL_State f Sskip k e le) m'

  | clight_corestep_set:   forall f id a k e le m v,
      eval_expr ge e le m a v ->
      clight_corestep (CL_State f (Sset id a) k e le) m
        (CL_State f Sskip k e (PTree.set id v le)) m

  | clight_corestep_call:   forall f optid a al k e le m tyargs tyres vf vargs fd,
      classify_fun (typeof a) = fun_case_f tyargs tyres ->
      eval_expr ge e le m a vf ->
      eval_exprlist ge e le m al tyargs vargs ->
      Genv.find_funct ge vf = Some fd ->
      type_of_fundef fd = Tfunction tyargs tyres ->
      clight_corestep (CL_State f (Scall optid a al) k e le) m
        (CL_Callstate fd vargs (Kcall optid f e le k)) m

(* WE DO NOT TREAT BUILTINS
  | clight_corestep_builtin:   forall f optid ef tyargs al k e le m vargs t vres m',
      eval_exprlist ge e le m al tyargs vargs ->
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_State f (Sbuiltin optid ef tyargs al) k e le) m
         (CL_State f Sskip k e (set_opttemp optid vres le)) m'
*)

  | clight_corestep_seq:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Ssequence s1 s2) k e le) m
        (CL_State f s1 (Kseq s2 k) e le) m
  | clight_corestep_skip_seq: forall f s k e le m,
      clight_corestep (CL_State f Sskip (Kseq s k) e le) m
        (CL_State f s k e le) m
  | clight_corestep_continue_seq: forall f s k e le m,
      clight_corestep (CL_State f Scontinue (Kseq s k) e le) m
        (CL_State f Scontinue k e le) m
  | clight_corestep_break_seq: forall f s k e le m,
      clight_corestep (CL_State f Sbreak (Kseq s k) e le) m
        (CL_State f Sbreak k e le) m

  | clight_corestep_ifthenelse:  forall f a s1 s2 k e le m v1 b,
      eval_expr ge e le m a v1 ->
      bool_val v1 (typeof a) = Some b ->
      clight_corestep (CL_State f (Sifthenelse a s1 s2) k e le) m
        (CL_State f (if b then s1 else s2) k e le) m

  | clight_corestep_loop: forall f s1 s2 k e le m,
      clight_corestep (CL_State f (Sloop s1 s2) k e le) m
        (CL_State f s1 (Kloop1 s1 s2 k) e le) m
  | clight_corestep_skip_or_continue_loop1:  forall f s1 s2 k e le m x,
      x = Sskip \/ x = Scontinue ->
      clight_corestep (CL_State f x (Kloop1 s1 s2 k) e le) m
        (CL_State f s2 (Kloop2 s1 s2 k) e le) m
  | clight_corestep_break_loop1:  forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop1 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_skip_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sskip (Kloop2 s1 s2 k) e le) m
        (CL_State f (Sloop s1 s2) k e le) m
  | clight_corestep_break_loop2: forall f s1 s2 k e le m,
      clight_corestep (CL_State f Sbreak (Kloop2 s1 s2 k) e le) m
        (CL_State f Sskip k e le) m

  | clight_corestep_return_0: forall f k e le m m',
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn None) k e le) m
        (CL_Returnstate Vundef (call_cont k)) m'
  | clight_corestep_return_1: forall f a k e le m v v' m',
      eval_expr ge e le m a v ->
      sem_cast v (typeof a) f.(fn_return) = Some v' ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f (Sreturn (Some a)) k e le) m
        (CL_Returnstate v' (call_cont k)) m'
  | clight_corestep_skip_call: forall f k e le m m',
      is_call_cont k ->
      Mem.free_list m (blocks_of_env e) = Some m' ->
      clight_corestep (CL_State f Sskip k e le) m
        (CL_Returnstate Vundef k) m'

  | clight_corestep_switch: forall f a sl k e le m n,
      eval_expr ge e le m a (Vint n) ->
      clight_corestep (CL_State f (Sswitch a sl) k e le) m
        (CL_State f (seq_of_labeled_statement (select_switch n sl)) (Kswitch k) e le) m
  | clight_corestep_skip_break_switch: forall f x k e le m,
      x = Sskip \/ x = Sbreak ->
      clight_corestep (CL_State f x (Kswitch k) e le) m
        (CL_State f Sskip k e le) m
  | clight_corestep_continue_switch: forall f k e le m,
      clight_corestep (CL_State f Scontinue (Kswitch k) e le) m
        (CL_State f Scontinue k e le) m

  | clight_corestep_label: forall f lbl s k e le m,
      clight_corestep (CL_State f (Slabel lbl s) k e le) m
        (CL_State f s k e le) m

  | clight_corestep_goto: forall f lbl k e le m s' k',
      find_label lbl f.(fn_body) (call_cont k) = Some (s', k') ->
      clight_corestep (CL_State f (Sgoto lbl) k e le) m
        (CL_State f s' k' e le) m

  | clight_corestep_internal_function: forall f vargs k m e le m',
      function_entry f vargs m e le m' ->
      clight_corestep (CL_Callstate (Internal f) vargs k) m
        (CL_State f f.(fn_body) k e le) m'
(*no external step
  | step_external_function: forall ef targs tres vargs k m vres t m',
      external_call ef ge vargs m t vres m' ->
      clight_corestep (CL_Callstate (External ef targs tres) vargs k) m
         (CL_Returnstate vres k) m'
*)

  | clight_corestep_returnstate: forall v optid f e le k m,
      clight_corestep (CL_Returnstate v (Kcall optid f e le k)) m
        (CL_State f Sskip k e (set_opttemp optid v le)) m.

Lemma CL_corestep_not_at_external: forall m q m' q', clight_corestep q m q' m' -> CL_at_external q = None.