From: "Norman H. Cohen" <ncohen@watson.ibm.com>
To: "whiting_ms@corning.com (Matt Whiting)" <whiting_ms@corning.com>
Subject: Re: GNAT messages and the not operator (pitfall alert!)
Date: 1996/10/30
Date: 1996-10-30T00:00:00+00:00 [thread overview]
Message-ID: <327771EE.1237@watson.ibm.com> (raw)
In-Reply-To: 1996Oct29.145959.1@corning.com
whiting_ms@corning.com (Matt Whiting) wrote (referring to Figure 6.2 in
Ada as a Second Language):
> If I'm reading the p. 246 table correctly, -5 mod 4 (row 1, column 4, excluding
> the "header row and column"), should evaluate to 3. However, I just wrote a
> simple little program using ObjectAda V7.0 which evaluates to -1, which, BTW,
> is what I would have expected. Taking into account the warning on p. 245, I
> also tried -(5 mod 4). It does give the identical -1 result. Am I reading the
> table incorrectly?
You are indeed reading the table incorrectly. The entry to which you
refer occurs in the row marked "X mod 4" in the column for X = -5. Thus
it gives the value for (-5) mod 4, which is indeed 3, not the value of
-(5 mod 4), which is, of course -1.
(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.)
--
Norman H. Cohen
mailto:ncohen@watson.ibm.com
http://www.research.ibm.com/people/n/ncohen
next prev parent reply other threads:[~1996-10-30 0:00 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
1996-10-24 0:00 GNAT messages and the not operator (pitfall alert!) Robert Dewar
1996-10-24 0:00 ` Robert Dewar
1996-10-25 0:00 ` whiting_ms@corning.com (Matt Whiting)
1996-10-26 0:00 ` David C. Hoos, Sr.
1996-10-27 0:00 ` Robert Dewar
1996-10-28 0:00 ` Matthew S. Whiting
1996-10-26 0:00 ` John Herro
1996-10-26 0:00 ` Matthew Heaney
1996-10-29 0:00 ` Robert Dewar
1996-10-26 0:00 ` Robert Dewar
1996-10-29 0:00 ` John Herro
1996-10-29 0:00 ` Robert Dewar
1996-10-30 0:00 ` Dr. Peter E. Obermayer
1996-10-30 0:00 ` John Herro
1996-10-30 0:00 ` Robert Dewar
1996-11-01 0:00 ` User Password expiration date extractor? Stein-Aksel Basma
1996-10-29 0:00 ` GNAT messages and the not operator (pitfall alert!) Norman H. Cohen
1996-10-29 0:00 ` whiting_ms@corning.com (Matt Whiting)
1996-10-30 0:00 ` Robert Dewar
1996-10-30 0:00 ` Norman H. Cohen [this message]
1996-11-06 0:00 ` Richard A. O'Keefe
1996-11-18 0:00 ` Norman H. Cohen
1996-11-18 0:00 ` Robert Dewar
1996-10-30 0:00 ` David C. Hoos, Sr.
1996-10-30 0:00 ` whiting_ms@corning.com (Matt Whiting)
1996-10-30 0:00 ` Norman H. Cohen
1996-11-05 0:00 ` Robert Dewar
1996-10-28 0:00 ` Cary Jamison
1996-10-29 0:00 ` Robert Dewar
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