Passes a command to the POSIX threads debugger for execution.
    The results appear in the command view. Once the POSIX threads
    debugger command has been completed, control is returned to the
    OpenVMS debugger. You can get help on POSIX threads debugger
    commands by typing PTHREAD HELP.

    See the Guide to the POSIX Threads Library for more information
    about using the POSIX threads debugger.

    Related commands:

    o  SET EVENT FACILITY

    o  SET TASK|THREAD

    o  SHOW EVENT FACILITY

    o  SHOW TASK|THREAD