Definition Delta1 V G {C: compspecs}: tycontext :=
  make_tycontext ((1%positive,(Tfunction Tnil Tvoid cc_default))::nil) nil nil Tvoid V G nil.

Lemma in_map_sig {A B} (E:forall b b' : B, {b=b'}+{b<>b'}) y (f : A -> B) l : In y (map f l) -> {x : A | f x = y /\ In x l }.