From ea2cebaf7415f7f6778eff778fbd489a5d0fab4b Mon Sep 17 00:00:00 2001
From: Leonardo de Moura <leonardo@microsoft.com>
Date: Thu, 19 Dec 2019 12:03:13 -0800
Subject: [PATCH] fix: typo

---
 src/Init/Lean/Util/WHNF.lean | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Init/Lean/Util/WHNF.lean b/src/Init/Lean/Util/WHNF.lean
index 109e95b1d8..149b175c0a 100644
--- a/src/Init/Lean/Util/WHNF.lean
+++ b/src/Init/Lean/Util/WHNF.lean
@@ -288,7 +288,7 @@ else
     f' ← whnfCore f;
     if f'.isLambda then
       let revArgs := e.getAppRevArgs;
-      whnfCore $ f.betaRev revArgs
+      whnfCore $ f'.betaRev revArgs
     else do
       let done : Unit → m Expr := fun _ =>
         if f == f' then pure e else pure $ e.updateFn f';