Index: tests/coroutine/fibonacci.c
===================================================================
--- tests/coroutine/fibonacci.c	(revision adb6b30f3f83b2166bd82dc6c0ab895d1f2d68a7)
+++ tests/coroutine/fibonacci.c	(revision ae4af8101a1a39f5294fca4aa3450bd629e96e87)
@@ -6,11 +6,10 @@
 //
 // fibonacci.c -- 3-state finite-state machine
-
 //
 // Author           : Thierry Delisle
 // Created On       : Thu Jun  8 07:29:37 2017
 // Last Modified By : Peter A. Buhr
-// Last Modified On : Thu Aug 16 08:18:16 2018
-// Update Count     : 20
+// Last Modified On : Sat Aug 18 11:21:58 2018
+// Update Count     : 24
 //
 
@@ -39,5 +38,5 @@
 int main() {
 	Fibonacci f1, f2;
-	for ( int i = 1; i <= 10; i += 1 ) {
+	for ( 10 ) {										// print N Fibonacci values
 		sout | next( f1 ) | next( f2 ) | endl;
 	} // for
Index: tests/coroutine/pingpong.c
===================================================================
--- tests/coroutine/pingpong.c	(revision adb6b30f3f83b2166bd82dc6c0ab895d1f2d68a7)
+++ tests/coroutine/pingpong.c	(revision ae4af8101a1a39f5294fca4aa3450bd629e96e87)
@@ -10,6 +10,6 @@
 // Created On       : Wed Sep 20 11:55:23 2017
 // Last Modified By : Peter A. Buhr
-// Last Modified On : Wed Sep 20 13:41:39 2017
-// Update Count     : 26
+// Last Modified On : Sat Aug 18 11:31:11 2018
+// Update Count     : 28
 //
 
@@ -39,5 +39,5 @@
 }
 void main( PingPong & pingpong ) {						// ping's starter ::main, pong's starter ping
-	for ( unsigned int i = 0; i < pingpong.N; i += 1 ) {
+	for ( pingpong.N ) {								// N ping-pongs
 		sout | pingpong.name | endl;
 		cycle( *pingpong.part );
Index: tests/coroutine/prodcons.c
===================================================================
--- tests/coroutine/prodcons.c	(revision adb6b30f3f83b2166bd82dc6c0ab895d1f2d68a7)
+++ tests/coroutine/prodcons.c	(revision ae4af8101a1a39f5294fca4aa3450bd629e96e87)
@@ -10,11 +10,11 @@
 // Created On       : Mon Sep 18 12:23:39 2017
 // Last Modified By : Peter A. Buhr
-// Last Modified On : Tue Jan  2 12:17:01 2018
-// Update Count     : 47
+// Last Modified On : Sat Aug 18 12:55:10 2018
+// Update Count     : 51
 //
 
 #include <fstream.hfa>
 #include <coroutine.hfa>
-#include <stdlib.hfa>										// random
+#include <stdlib.hfa>									// random
 #include <unistd.h>										// getpid
 
@@ -29,5 +29,5 @@
 void main( Prod & prod ) with( prod ) {					// starter ::main
 	// 1st resume starts here
-	for ( int i = 0; i < N; i += 1 ) {
+	for ( i; N ) {										// N pairs of values
 		int p1 = random( 100 );
 		int p2 = random( 100 );