You should be familiar with several terms used in discussions of PL/I error and condition handling. The terms are listed below:
*--------------
|(SIZE):B:PROC;
|ON ERROR SNAP;
| .
| .
|
|CALL C;
| *--------
| |C:PROC;
| |
| |END C;
| *--------
|CALL D;
|END B;
*---------------
*--------- *---------
|D:PROC; |E:PROC;
|. |
|. |
| |
|CALL E; |
|END D; |END E;
*--------- *----------