Simple Rexx tracing

test.rex
/* Simple test */
Trace ?r
C = 'L'
-- lots of stuff here…
Say 'The time is' time(C)
Result:
       +++ "WindowsNT SUBROUTINE c:\Test.rex"
     3 *-* C = 'L'
       >>>   "L"
+++ Interactive trace. "Trace Off" to end debug, ENTER to Continue. +++

     5 *-* Say 'The time is' time(C)
       >>>   "L"
       >>>   "The time is 13:17:10.328000"
The time is 13:17:10.328000