fact: Definition Derive_P_A_2_nind (x y : Conf) := ex2 (fun a : Elt => dans a X) (fun a : Elt => fst x = cons a (fst y) /\ snd x = cons a (snd y)) \/ (exists a : Elt, ex2 (fun w : Word => cons a w = fst x) (fun w : Word => ex2 (fun u : Word => dans (couple a (word u)) R) (fun u : Word => Append u w = fst y))).
imports: Ensf Words more_words need Relations gram gram_g PushdownAutomata