Goal forall x : proc, x = alt Delta x.
intro.
elim A1.
apply A6.
Save A6'.
Section GUARDED.
Variable D : Set.
Variable d : D.
Variable x y : proc.
Variable z : D -> proc.
Variable a : act.
Variable B : bool.
Variable L : ehlist.

Axiom G8 : GRD x -> GRD y -> GRD (alt x y).