>>-TRACE--+-+--------+----------------------+--;---------------><
          | '-number-'                      |      
          |               .-Normal--------. |      
          '-+-----------+-+---------------+-'      
            | .-------. | +-All-----------+        
            | V       | | +-Commands------+        
            '---+-?-+-+-' +-Error---------+        
                '-!-'     +-Failure-------+        
                          +-Intermediates-+        
                          +-Labels--------+        
                          +-Off-----------+        
                          +-Results-------+        
                          '-Scan----------'        

>>-TRACE--+----------------------+--;--------------------------><
          +-string---------------+      
          +-symbol---------------+      
          '-+-------+-expression-'      
            '-VALUE-'                   

TRACE controls the tracing action (that is, how much is displayed to the user) during processing of a REXX program. (Tracing describes some or all of the clauses in a program, producing descriptions of clauses as they are processed.) TRACE is mainly used for debugging. Its syntax is more concise than that of other REXX instructions because TRACE is usually entered manually during interactive debugging. (This is a form of tracing in which the user can interact with the language processor while the program is running.) For this use, economy of key strokes is especially convenient.

If specified, the number must be a whole number.

The option that follows TRACE or the result of evaluating expression determines the tracing action. You can omit the subkeyword VALUE if expression does not begin with a symbol or a literal string (that is, if it starts with a special character, such as an operator or parenthesis).