Revert spurious change to ref file.

b70f1bcb · Joseph Tassarotti · dfefb918 · b70f1bcb
Commit b70f1bcb authored May 22, 2019 by Joseph Tassarotti
--- a/tests/proofmode.ref
+++ b/tests/proofmode.ref
@@ -118,7 +118,7 @@ Tactic failure: iSpecialize: cannot instantiate (⌜φ⌝ → P -∗ False)%I wi
  ============================
  "H1" : ⌜S (S (S x)) = y⌝
  --------------------------------------□
-  "H2" : ⌜1 + y = z⌝
+  "H2" : ⌜(1 + y)%nat = z⌝
  --------------------------------------∗
  ⌜S (S (S x)) = y⌝