proposition: Lemma interp_eq_compat : forall rho1 rho2 l, rho1 (blit l) = rho2 (blit l) -> interp rho1 l = interp rho2 l.
proof: Proof. unfold interp, Var.interp;intros rho1 rho2 l Heq;rewrite Heq;trivial. Qed.
imports: List Bool Int63 Psatz Ring63 PArray Misc Ring