Standard extensions (logical exclusive or)

[Fred Yankowski]

Although "A != B" does not work as a C implementation of logical-
exclusive-or, "!A != !B" (or "!!A == !B") does, since the '!'
operator has the effect of converting an integer into a "canonical"
boolean value:  zero or one (and negating the logical sense, of
course).  Logical equivalence for arbitrary integers can be
similarly defined by "!A == !B".


    Fred Yankowski ::: AT&T Bell Laboratories ::: ihnp4!iham1!fcy