(*Lemma SR: forall pc nc , (forall s, clause_denote pc s /\ clause_denote nc s) -> forall s, setd clause_denote inter TT (spatial_resolution pc nc) s. *)

Lemma unfolding1'_sound: forall  sigma2 sigma0 sigma1 p sig2' s,
In (p,sig2') (unfolding1' sigma0 sigma1 sigma2) ->
space_denote sig2' s ->
(pure_atom_denote p s \/ space_denote (sigma0++sigma2) s).