CLHS: Issue NOT-AND-NULL-RETURN-VALUE Writeup

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## Issue NOT-AND-NULL-RETURN-VALUE Writeup

    Forum:          Public Review
    Issue:          NOT-AND-NULL-RETURN-VALUE
    References:     Margolin's public review comment #6
    		Pitman's public review comment #4
    Category:       CHANGE
    Edit history:   12 Sept 1993, Version 1 by Loosemore
    Status:		Proposal X3J13-MARCH-1993 passed 6-2 at the March 1993 meeting

    Problem description:

      Due to an editing error, the semantics of NOT and NULL have been
      changed to say that they return true/false rather than T/NIL.  This
      change was accidentally introduced; there was no foundation for it in
      any X3J13 vote.

    Proposal (NOT-AND-NULL-RETURN-VALUE:X3J13-MARCH-1993):

      Restore the CLtL semantics.

    Rationale:

      This is what users expect.  It supports idioms such as
        (EQ (NOT (NOT X)) 'T)
      and
        (DEFUN BOOLEAN-EQUAL-P (X Y) (EQ (NOT X) (NOT Y)))

    Current practice:

      Unknown.

    Cost to implementors:

      Unknown.

    Cost to users:

      None.

    Aesthetics:

    Editorial impact:

    Discussion:

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