An integer expression that specifies the line number in procedure (based at line 1 of the debug listing) where you want to cancel the breakpoint. A positive integer greater than or equal to 1 represents a line number in the specified 
procedure file. Zero (0) or a negative integer value represents the first executable line of the main procedure block in the specified 
procedure file. If you do not specify 
line-number, the method cancels the breakpoint at the first executable line of 
procedure file.
 
      If you invoke DEBUGGER:CANCEL-BREAK ( procedure , 
line-number ) on the same line that is specified by 
procedure and 
line-number, the existing breakpoint on the specified line occurs the first time it is executed. The breakpoint is cancelled only on the second and succeeding executions of the line.