(* File: Forces_Gamma.v  (last edited on 27/10/2000) (c) Klaus Weich  *)
Require Export In_Gamma.
Require Export Forces_NGamma.
Definition forces_gamma (gamma : flist) (work : nf_list)
(k : kripke_tree) := forall a : form, in_gamma gamma work a -> forces_t k a.

Lemma forces_gamma_cons_gamma :
forall (gamma : flist) (work : nf_list) (k : kripke_tree) (a : form),
forces_t k a ->
forces_gamma gamma work k -> forces_gamma (a :: gamma) work k.