>V> - Variable value - The data traced is the contents
of a variable.
>L> - Literal value - The data traced is a literal
(string, uninitialized variable, or constant).
>O> - Operation result - The data traced is the result
of an operation on two terms.
1 /************************* REXX ***************************/
2 /* This program uses the TRACE instruction to show how */
3 /* an expression is evaluated, operation by operation. */
4 /**********************************************************/
5 a = 9
6 y = 2
7 TRACE I
8
9 IF a + 1 > 5 * y THEN
10 SAY 'a is big enough.'
11 ELSE NOP /* No operation on the ELSE path */
9 *-* IF a + 1 > 5 * y
>V> "9"
>L> "1"
>O> "10"
>L> "5"
>V> "2"
>O> "10"
>O> "0"
The 9 is the line number. The *-* indicates that what follows is the data from the program, IF a + 1 < 5 * y. The remaining lines break down all the expressions.