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From: ok@goanna.cs.rmit.edu.au (Richard A. O'Keefe)
Subject: Re: GNAT messages and the not operator (pitfall alert!)
Date: 1996/11/06
Message-ID: <55p8b6$l29$1@goanna.cs.rmit.edu.au>#1/1
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references: <dewar.846162354@merv> <dewar.846163972@merv>
 <32762A30.D2D@watson.ibm.com> <1996Oct29.145959.1@corning.com>
 <327771EE.1237@watson.ibm.com>
organization: Comp Sci, RMIT, Melbourne, Australia
nntp-posting-user: ok
newsgroups: comp.lang.ada
Date: 1996-11-06T00:00:00+00:00
List-Id: <comp.lang.ada>


"Norman H. Cohen" <ncohen@watson.ibm.com> writes:

>(As you noted, "-5 mod 4" means, surprisingly, "-(5 mod 4)", so the
>table entry for X mod 4 when X = -5 is NOT the value of -5 mod 4.)

I don't understand what is surprising about -5 mod 4 being the same
as -(5 mod 4).  After all, you expect -x to be the same as 0-x,
and 0 - 5 mod 4 is
	<operand 1> ADD <operand 2> MULTIPLY <operand 3>
which naturally groups as
	<operand 1> ADD (<operand 2> MULTIPLY <operand 3>)

The grouping, at least, is identical in Pascal.
-- 
Mixed Member Proportional---a *great* way to vote!
Richard A. O'Keefe; http://www.cs.rmit.edu.au/%7Eok; RMIT Comp.Sci.