From 11311bcaa7a32b6755afb64e343ae87d7f06cac6 Mon Sep 17 00:00:00 2001
From: Jan Nieuwenhuizen <janneke@gnu.org>
Date: Sun, 21 May 2017 12:33:16 +0200
Subject: [PATCH] mes: Add negate.

* module/mes/scm.mes (negate): New function.
---
 module/mes/scm.mes | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/module/mes/scm.mes b/module/mes/scm.mes
index 6e58bfff..50ed221f 100644
--- a/module/mes/scm.mes
+++ b/module/mes/scm.mes
@@ -355,3 +355,7 @@
       (let ((y (car rest)))
         (let ((z (if (< x y) x y)))
           (apply min (cons z (cdr rest)))))))
+
+(define (negate proc)
+  (lambda args
+    (not (apply proc args))))