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: