(** Computational version of type_eq **)

Definition eqb_option {A} (f: A -> A -> bool) (x y: option A) : bool :=
  match x, y with
  | None, None => true
  | Some x' , Some y' => f x' y'
 | _, _ => false
  end.Definition eqb_attr (a b: attr) : bool :=
 match a, b with
 | mk_attr av an, mk_attr bv bn => eqb av bv && eqb_option N.eqb an bn
 end.Definition eqb_floatsize (a b: floatsize) : bool :=
 match a , b with
 | F32, F32 => true
 | F64, F64 => true
 | _, _ => false
 end.Definition eqb_ident : ident -> ident -> bool := Pos.eqb.Definition eqb_intsize (a b: intsize) : bool :=
 match a , b with
 | I8, I8 => true
 | I16, I16 => true
 | I32, I32 => true
 | IBool, IBool => true
 | _, _ => false
 end.Definition eqb_signedness (a b : signedness) :=
 match a, b with
 | Signed, Signed => true
 | Unsigned, Unsigned => true
 | _, _ => false
 end.Definition eqb_calling_convention (a b: calling_convention) :=
 andb (eqb (cc_vararg a) (cc_vararg b))
     (andb  (eqb (cc_unproto a) (cc_unproto b))
      (eqb (cc_structret a) (cc_structret b))).Fixpoint eqb_type (a b: type) {struct a} : bool :=
 match a, b with
 | Tvoid, Tvoid => true
 | Tint ia sa aa, Tint ib sb ab => andb (eqb_intsize ia ib)
                                                    (andb (eqb_signedness sa sb) (eqb_attr aa ab))
 | Tlong sa aa, Tlong sb ab => andb (eqb_signedness sa sb) (eqb_attr aa ab)
 | Tfloat sa aa, Tfloat sb ab => andb (eqb_floatsize sa sb) (eqb_attr aa ab)
 | Tpointer ta aa, Tpointer tb ab => andb (eqb_type ta tb) (eqb_attr aa ab)
 | Tarray ta sa aa, Tarray tb sb ab => andb (eqb_type ta tb)
                                                                   (andb (Zeq_bool sa sb) (eqb_attr aa ab))
 | Tfunction sa ta ca, Tfunction sb tb cb =>
       andb (andb (eqb_typelist sa sb) (eqb_type ta tb)) (eqb_calling_convention ca cb)
 | Tstruct ia aa, Tstruct ib ab => andb (eqb_ident ia ib) (eqb_attr aa ab)
 | Tunion ia aa, Tunion ib ab => andb (eqb_ident ia ib) (eqb_attr aa ab)
 | _, _ => false
 end
with eqb_typelist (a b: typelist)  {struct a}: bool :=
  match a, b with
  | Tcons ta ra, Tcons tb rb => andb (eqb_type ta tb) (eqb_typelist ra rb)
  | Tnil, Tnil => true
  | _ , _ => false
  end.Scheme eqb_type_sch := Induction for type Sort Prop
  with eqb_typelist_sch := Induction for  typelist Sort Prop.Definition eqb_member (it1 it2: ident * type): bool :=
  eqb_ident (fst it1) (fst it2) && eqb_type (snd it1) (snd it2).Definition eqb_su (su1 su2: struct_or_union): bool :=
  match su1, su2 with
  | Struct, Struct
  | Union, Union => true
  | _, _ => false
  end.

Lemma eqb_type_false: forall a b, eqb_type a b = false <-> a<>b.