Ltac InvApproxRegs :=
  match goal with
  | [ H: _ :: _ = _ :: _ |- _ ] =>
        injection H; clear H; intros; InvApproxRegs
  | [ H: ?v = AE.get ?r ae |- _ ] =>
        generalize (MATCH r); rewrite <- H; clear H; intro; InvApproxRegs
  | _ => idtac
  end.Ltac SimplVM :=
  match goal with
  | [ H: vmatch _ ?v (I ?n) |- _ ] =>
      let E := fresh in
      assert (E: v = Vint n) by (inversion H; auto);
      rewrite E in *; clear H; SimplVM
  | [ H: vmatch _ ?v (F ?n) |- _ ] =>
      let E := fresh in
      assert (E: v = Vfloat n) by (inversion H; auto);
      rewrite E in *; clear H; SimplVM
  | [ H: vmatch _ ?v (FS ?n) |- _ ] =>
      let E := fresh in
      assert (E: v = Vsingle n) by (inversion H; auto);
      rewrite E in *; clear H; SimplVM
  | [ H: vmatch _ ?v (Ptr(Gl ?id ?ofs)) |- _ ] =>
      let E := fresh in
      assert (E: Val.lessdef v (Genv.symbol_address ge id ofs)) by (eapply vmatch_ptr_gl; eauto);
      clear H; SimplVM
  | [ H: vmatch _ ?v (Ptr(Stk ?ofs)) |- _ ] =>
      let E := fresh in
      assert (E: Val.lessdef v (Vptr sp ofs)) by (eapply vmatch_ptr_stk; eauto);
      clear H; SimplVM
  | _ => idtac
  end.

Lemma eval_static_shift_correct: forall s n, eval_shift s (Vint n) = Vint (eval_static_shift s n).