(* File: Forces_NGamma.v  (last edited on 27/10/2000) (c) Klaus Weich  *)
Require Export Le_Ks.
Definition forces_ngamma (work : nf_list) (ds : disjs)
(ni : nested_imps) (ai : atomic_imps) (a : atoms)
(k : kripke_tree) :=
forall c : normal_form,
in_ngamma work ds ni ai a c -> forces_t k (nf2form c).
(********************************************************************)

Lemma forces_ngamma_cons_work :
forall (c : normal_form) (work : nf_list) (ds : disjs)
(ni : nested_imps) (ai : atomic_imps) (a : atoms)
(k : kripke_tree),
forces_t k (nf2form c) ->
forces_ngamma work ds ni ai a k -> forces_ngamma (c :: work) ds ni ai a k.