From d844c38df29d4bc6a05b3a9c8535acddf803a5c0 Mon Sep 17 00:00:00 2001
From: Jeremy Dormitzer <jeremy.dormitzer@gmail.com>
Date: Sun, 14 Jul 2019 22:58:54 -0400
Subject: [PATCH] Troubleshoot negation

Negation still doesn't seem to be working, although everything else
looks good.
---
 src/sicp_logic/evaluator.clj | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/sicp_logic/evaluator.clj b/src/sicp_logic/evaluator.clj
index 68be48a..addee83 100644
--- a/src/sicp_logic/evaluator.clj
+++ b/src/sicp_logic/evaluator.clj
@@ -21,7 +21,7 @@
 (defn negate [db operands input-frames]
   (filter
    (fn [frame]
-     (empty? (qeval db operands [frame])))
+     (empty? (qeval db (first operands) [frame])))
    input-frames))
 
 (defn execute [exp]
@@ -39,7 +39,8 @@
            call
            frame
            (fn [v f]
-             (throw (IllegalArgumentException. (str "Unknown pattern variable -- LISP-VALUE: " v))))))
+             (throw
+              (IllegalArgumentException. (str "Unknown pattern variable -- LISP-VALUE: " v))))))
        [frame]
        []))
    input-frames))