--- rpn/README.orig	2005-09-28 22:21:03.000000000 -0400
+++ rpn/README	2005-09-28 22:22:31.000000000 -0400
@@ -10,6 +10,7 @@
 -   Subtraction
 *   Multiplication
 /   Division
+%   Modulus (fmod(3))
 c   Change the sign of the top element
 
 .   Print the top element
--- rpn/Makefile.orig	2005-09-28 22:22:45.000000000 -0400
+++ rpn/Makefile	2005-09-28 22:23:06.000000000 -0400
@@ -3,4 +3,4 @@
 # Licensed under the Open Software License version 2.1
 
 rpn: rpn.o stack.o lexer.o
-	$(CC) $(CFLAGS) $^ -o $@
+	$(CC) $(CFLAGS) $^ -lm -o $@
--- rpn/rpn.c.orig	2005-09-28 22:20:58.000000000 -0400
+++ rpn/rpn.c	2005-09-28 22:22:08.000000000 -0400
@@ -6,6 +6,7 @@
  */
 
 #include <stdio.h>
+#include <math.h>
 
 double val;
 
@@ -39,6 +40,10 @@
 			x = pop();
 			push(x / pop());
 			break;
+		case '%':
+			x = pop();
+			push(fmod(x, pop()));
+			break;
 		case 'c':
 			push(-pop());
 			break;