The SET STEP command establishes default qualifiers for
    subsequent STEP commands. The parameters that you specify in
    the SET STEP command have the same names as the qualifiers for
    the STEP command. The following parameters affect where the STEP
    command suspends execution after a step:

       BRANCH
       CALL
       EXCEPTION
       INSTRUCTION
       LINE
       RETURN
       SEMANTIC_EVENT (Alpha only)

    The following parameters affect what output is seen when a STEP
    command is executed:

       [NO]SILENT
       [NO]SOURCE

    The following parameters affect what happens at a routine call:

       INTO
       OVER
       [NO]SHARE
       [NO]SYSTEM

    You can override the current STEP defaults for the duration of a
    single STEP command by specifying other qualifiers. Use the SHOW
    STEP command to identify the current STEP defaults.

    Enabling screen mode by pressing PF1-PF3 enters the SET STEP
    NOSOURCE command as well as the SET MODE SCREEN command.
    Therefore, any display of source code in output and DO displays
    that would result from a STEP command or from a breakpoint,
    tracepoint, or watchpoint being triggered is suppressed, to
    eliminate redundancy with the source display.

    Related commands:

       SHOW STEP
       STEP