1. After a breakpoint has been established, execution of the program is interrupted just before the specified location. A breakpoint remains active as long as it is not removed.

2. Breakpoints can be set before execution of the program but are automatically deleted after the execution terminates. A breakpoint may be explicitly removed by calling the function XPRMdbg_clearbrkp.

3. The line index value -1 is a special code to establish a breakpoint just before the execution terminates (when there is no error). The debugger function is therefore called on the last statement of the program or at a call to the exit function.