DBG> SET IMAGE SHARE1
  DBG> SET MODULE SUBR
  DBG> SET BREAK SUBR

      This sequence of commands shows how to set a breakpoint on
      routine SUBR in module SUBR of shareable image SHARE1. The SET
      IMAGE command sets the debugging context to SHARE1. The SET
      MODULE command loads the symbol records of module SUBR into
      the run-time symbol table (RST). The SET BREAK command sets a
      breakpoint on routine SUBR.