(** "Cooperating" semantics impose additional constraints; in particular,
   they require that the memories produced by coresteps contain no dangling
   pointers. *)

Record CoopCoreSem {G C} :=
  { coopsem :> CoreSemantics G C mem;
    corestep_fwd : forall g c m c' m' (CS: corestep coopsem g c m c' m'),
      mem_forward m m'
(*;
    corestep_wdmem: forall g c m c' m' (CS: corestep coopsem g c m c' m'),
      mem_wd m -> mem_wd m'*)
   (*Doesn't make sense any longer: initial_mem is a property of program, not cores;
    initmem_wd: forall g m d, initial_mem coopsem g m d -> mem_wd m*)
}.(** "Cooperating" semantics impose additional constraints; in particular,
   they require that the memories produced by coresteps contain no dangling
   pointers. *)

Record CoopCoreSem {G C} :=
  { coopsem :> CoreSemantics G C mem;
    corestep_fwd : forall g c m c' m' (CS: corestep coopsem g c m c' m'),
      mem_forward m m'
(*;
    corestep_wdmem: forall g c m c' m' (CS: corestep coopsem g c m c' m'),
      mem_wd m -> mem_wd m'*)
   (*Doesn't make sense any longer: initial_mem is a property of program, not cores;
    initmem_wd: forall g m d, initial_mem coopsem g m d -> mem_wd m*)
}.(** "Cooperating" semantics impose additional constraints; in particular,
   they require that the memories produced by coresteps contain no dangling
   pointers. *)

Record CoopCoreSem {G C} :=
  { coopsem :> CoreSemantics G C mem;
    corestep_fwd : forall g c m c' m' (CS: corestep coopsem g c m c' m'),
      mem_forward m m'
(*;
    corestep_wdmem: forall g c m c' m' (CS: corestep coopsem g c m c' m'),
      mem_wd m -> mem_wd m'*)
   (*Doesn't make sense any longer: initial_mem is a property of program, not cores;
    initmem_wd: forall g m d, initial_mem coopsem g m d -> mem_wd m*)
}.

Lemma corestep_plus_fwd: forall g c m c' m' (CS:corestep_plus coopsem g c m c' m'), mem_forward m m'.