--- include/NTL/tools.h	2008-03-04 15:35:02.000000000 -0800
+++ include/NTL/tools.h.modified	2008-04-17 12:24:41.000000000 -0700
@@ -249,6 +249,12 @@
 char IntValToChar(long a);
 
 
+/*
+  This function is not present in vanilla NTL 5.4.2.
+  See tools.c for documentation.
+ */
+void SetErrorCallbackFunction(void (*func)(const char *s, void *context), void *context);
+
 
 void Error(const char *s);