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HELP CANCEL                                     Steven Hardy, January 1978

    cancel word1 word2 word3 ... ;

-cancel- is a macro which simplifies the use of *SYSCANCEL.

This cancels all words between -cancel- and the semi-colon.  The mechanics
of cancellation are complex and you should rarely (if ever) need to use
it.  Its effect is that any identifier cancelled can be used afresh with no
thought to its use in the past.  Any existing references to the identifier
will still refer to the old usage - any new use is independent. If you
wish to define a procedure whose name is already used by the POP11 system
(e.g. -member-) you will first have to CANCEL it, e.g.

    cancel member;

is equivalent to:


-cancel- will NOT cancel protected words.  If you want to cancel a
protected word you either use *SYSCANCEL or first unprotect the word using

    *SYSCANCEL     - cancels a word as a variable or constant
    *SYSPROTECT    - protects a word from assingment or cancellation
    *SYSUNPROTECT  - to unprotect protected words.
    *VARS          - on variables and their declaration
    *CONSTANT      - on constants and their declaration
    *SYSCANCELWORD - removes a word from the dictionary
    *SYSSYNONYM    - makes two variables or constants synonymous