XOR

[Guy Steele <gls@THINK-AQUINAS.ARPA>]

    Date: Tue, 17 Dec 85 10:45 EST
    From: Kent M Pitman <KMP@SCRC-STONY-BROOK.ARPA>

     * Why is OR not called IOR? (Or, why is LOGIOR not called LOGOR)

I dunno.  That goes way back into history.

     * Why aren't there special forms called NAND, NOR, CLR, SET(!), EQV, 
       ORC1, ANDC2, ... which do the other logical operations. If there were,
       such forms (whatever they were named), some would have very peculiar 
       rules about when evaluation could be allowed to stop, and I'm not sure 
       if I'd want to have to learn them.

One problem is that NAND and NOR are not associative.  They could reasonably
be restricted to being two-place.  So could XOR, for that matter.