--- ray/src/common/erf.c	2003/02/22 02:07:22	3.1
+++ ray/src/common/erf.c	2013/08/03 17:53:46	3.2
@@ -1,10 +1,12 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: erf.c,v 3.1 2003/02/22 02:07:22 greg Exp $";
+static const char	RCSid[] = "$Id: erf.c,v 3.2 2013/08/03 17:53:46 greg Exp $";
 #endif
 #ifndef lint
 static	char sccsid[] = "@(#)erf.c 1.1 87/12/21 SMI"; /* from UCB 4.1 12/25/82 */
 #endif
 
+#include "rtmath.h"
+
 /*
 	C program for floating point error function
 
@@ -71,8 +73,7 @@ static double q2[]  = {
 };
 
 double
-erf(arg) double arg;{
-	double erfc();
+erf(double arg) {
 	int sign;
 	double argsq;
 	double d, n;
@@ -97,9 +98,7 @@ erf(arg) double arg;{
 }
 
 double
-erfc(arg) double arg;{
-	double erf();
-	double exp();
+erfc(double arg) {
 	double n, d;
 	int i;