From 848dccd25d0b3c5f9662e0fd83740b2894280ed5 Mon Sep 17 00:00:00 2001
From: Johan Wiltink <johan@wilt.ink>
Date: Thu, 14 Apr 2022 05:21:05 +0200
Subject: [PATCH] fixes #87

---
 src/lambda-calculus.js | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/lambda-calculus.js b/src/lambda-calculus.js
index aa117e6..ff8f7b3 100644
--- a/src/lambda-calculus.js
+++ b/src/lambda-calculus.js
@@ -382,10 +382,9 @@ function evalLC(term) {
           env = lastEnv;
         } else { // lastTerm is a JS function
           const res = lastTerm(term);
-          if ( res.term ) {
-            ({term, env} = res);
-            if ( ! env ) env = new Env;
-          } else
+          if ( res?.term )
+            ( {term, env=new Env} = res );
+          else
             term = res;
         }
       }