Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!munnari.oz.au!cs.mu.oz.au!ok
From: ok@cs.mu.oz.au (Richard O'Keefe)
Newsgroups: comp.lang.c
Subject: Re: ambiguous ?
Message-ID: <2521@munnari.oz.au>
Date: 25 Oct 89 05:25:09 GMT
References: <1989Oct21.071319.8839@utzoo.uucp> <14106@lanl.gov> <11401@smoke.BRL.MIL>
Sender: news@cs.mu.oz.au
Lines: 14

In article <11401@smoke.BRL.MIL>, gwyn@smoke.BRL.MIL (Doug Gwyn) writes:
> In article <2493@munnari.oz.au> ok@cs.mu.oz.au (Richard O'Keefe) writes:
> >you can use & and |.
 
> & and | aren't really Boolean operators in the normal use of the term
> in the context in which this arose; they're bitwise integer operators.

I know perfectly well what & and | are, but if you build up expressions
out of comparisons (E1 <relop> E2), negations (using ! rather than ~),
and & and |, you can't tell the difference.  The difference only shows
up when some of the leaves have values other than 0 or 1, and with
C's comparison operators that can't happen.  It remains true that you
can *USE* & and | as versions of "and" and "or" that are commutative,
associative, &c.