CANCEL SOURCE cancels the effect of a previous SET SOURCE
    command. The nature of this cancellation depends on the
    qualifiers activated in previous SET SOURCE commands. See the
    CANCEL SOURCE examples to see how CANCEL SOURCE and SET SOURCE
    interact.

    When you issue a SET SOURCE command, be aware that one of the
    two qualifiers -/LATEST or /EXACT-will always be active. These
    qualifiers affect the debugger search method. The /LATEST
    qualifier directs the debugger to search for the version last
    created (the highest-numbered version in your directory). The
    /EXACT qualifier directs the debugger to search for the version
    last compiled (the version recorded in the debugger symbol table
    created at compile time). For example, a SET SOURCE/LATEST
    command might search for SORT.FOR;3 while a SET SOURCE/EXACT
    command might search for SORT.FOR;1.

    CANCEL SOURCE without the /DISPLAY or /EDIT qualifier cancels the
    effect of both SET SOURCE/DISPLAY and SET SOURCE/EDIT, if both
    were previously given.

    The /DISPLAY qualifier is needed when the files to be displayed
    are no longer in the compilation directory.

    The /EDIT qualifier is needed when the files used for the display
    of source code are different from the editable files. This is the
    case with Ada programs. For Ada programs, the (SET,SHOW,CANCEL)
    SOURCE commands affect the search of files used for source
    display (the "copied" source files in Ada program libraries);
    the (SET,SHOW,CANCEL) SOURCE/EDIT commands affect the search of
    the source files that you edit when using the EDIT command.

    For information specific to Ada programs, see the
    Language_Support Ada help topic.

    Related commands:

       (SET,SHOW) SOURCE