Definition semax_equiv {CS: compspecs} {Espec: OracleKind} c1 c2: Prop := forall Delta P Q, semax Delta P c1 Q <-> semax Delta P c2 Q.

Lemma semax_unfold_Ssequence: forall {CS: compspecs} {Espec: OracleKind} c1 c2, unfold_Ssequence c1 = unfold_Ssequence c2 -> (forall P Q Delta, @semax CS Espec Delta P c1 Q -> @semax CS Espec Delta P c2 Q).