Definition classify_binarith' (ty1: type) (ty2: type) :=
  match stupid_typeconv ty1, stupid_typeconv ty2 with
  | Tint i1 s1 _, Tint i2 s2 _ => bin_case_i 
    match i1, s1, i2, s2 with
    | I32, Unsigned, _, _ => Unsigned
    | _, _, I32, Unsigned => Unsigned
    | _, _, _, _ => Signed
    end
  | Tint _ _ _, Tlong s _ => bin_case_l s
  | Tlong s _, Tint _ _ _ => bin_case_l s
  | Tlong s1 _, Tlong s2 _ => bin_case_l
    match s1, s2 with
    | Signed, Signed => Signed
    | _, _ => Unsigned
    end
  | Tfloat F32 _, Tfloat F32 _ => bin_case_s
  | Tfloat _ _, Tfloat _ _ => bin_case_f
  | Tfloat F64 _, (Tint _ _ _ | Tlong _ _) => bin_case_f
  | (Tint _ _ _ | Tlong _ _), Tfloat F64 _ => bin_case_f
  | Tfloat F32 _, (Tint _ _ _ | Tlong _ _) => bin_case_s
  | (Tint _ _ _ | Tlong _ _), Tfloat F32 _ => bin_case_s
  | _, _ => bin_default
  end.Definition binarithType' t1 t2 ty deferr reterr : tc_assert :=
  match classify_binarith' t1 t2 with
  | Cop.bin_case_i sg =>  tc_bool (is_int32_type ty) reterr
  | Cop.bin_case_l sg => tc_bool (is_long_type ty) reterr
  | Cop.bin_case_f   => tc_bool (is_float_type ty) reterr
  | Cop.bin_case_s   => tc_bool (is_single_type ty) reterr
  | Cop.bin_default => tc_FF deferr
  end.

Lemma classify_binarith_eq: classify_binarith = classify_binarith'.