(* File: NSound.v  (last edited on 27/10/2000) (c) Klaus Weich  *)
Require Export Le_Ks.
Require Export Derivable_Tools.
Definition nsound (work : nf_list) (ds : disjs) (ni : nested_imps)
(ai : atomic_imps) (a : atoms) (context : flist) :=
forall c : normal_form,
in_ngamma work ds ni ai a c -> Derivable context (nf2form c).
intros work ds ni1 ni2 ai a context eq12 sound.
unfold nsound in |- *.
intros c in_ngamma.
apply sound.
apply in_ngamma_eqv with ni2.
apply eqv_sym; assumption.
assumption.
Qed.
intros work ds ni1 ni2 ai a context le sound.
unfold nsound in |- *.
intros c in_ngamma.
apply sound.
apply in_ngamma_ge with ni2; assumption.
Qed.
intros work ds ni1 ni2 ai a context le sound.
unfold nsound in |- *.
intros c in_ngamma.
apply sound.
apply in_ngamma_le with ni2; assumption.
Qed.
(***********************************************************************)
intros i j work ds ni ai a context sound.
unfold nsound in |- *.
intros c in_ngamma.
apply sound.
apply in_ngamma_shift_ds_work; assumption.
Qed.
intros x work ds ni ai a context sound.
unfold nsound in |- *.
intros c in_ngamma.
apply sound.
apply in_ngamma_shift_ni_work; assumption.
Qed.
intros i b work ds ni ai ai' a context equiv_ins sound.
unfold nsound in |- *.
intros c in_ngamma.
apply sound.
apply in_ngamma_shift_ai_work with ai'; assumption.
Qed.
intros i work ds ni ai a a' context equiv_ins sound.
unfold nsound in |- *.
intros c in_ngamma.
apply sound.
apply in_ngamma_shift_a_work with a'; assumption.
Qed.

Lemma nsound_shift_work_ni_x_ni :
forall (x : nested_imp) (work : nf_list) (ds : disjs)
(ni1 ni2 : nested_imps) (ai : atomic_imps) (a : atoms)
(context : flist),
nsound (NImp_NF (nested_imp2nimp x) :: work) ds (ni1 ++ ni2) ai a context ->
nsound work ds (ni1 ++ x :: ni2) ai a context.