From: "Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org>
Subject: Re: What is the history behind Natural'First = 0 ?
Date: Fri, 1 May 2020 12:13:12 +0200
Date: 2020-05-01T12:13:12+02:00 [thread overview]
Message-ID: <r8gsno$dff$1@dont-email.me> (raw)
In-Reply-To: <9f0215ca-2760-47cf-a7cb-50184892e1d0@googlegroups.com>
On 5/1/20 6:51 AM, reinert wrote:
>
> There is no consensus about including 0 among the natural numbers.
Precisely, so Ichbiah was free to use Natural for whichever definition he
considered best. There was a need for subtypes with lower bounds of 0 and 1, and
those subtypes needed names, and Ichbiah chose Natural and Positive for them.
This seems like a good choice; if Natural is used for the latter, I cannot think
of a decent name for the former (Non_Negative? Natural_Plus_Zero?). Given the
obvious alternative name Positive for the subtype beginning with 1, it seems
pragmatic to use Natural for the subtype beginning with 0.
IIRC, Natural and Positive existed in Ada 80.
> Is the key point here: "the standard ISO 80000-2" ?
I doubt it, since that standard didn't exist in 1980.
--
Jeff Carter
"Why, the Mayflower was full of Fireflies, and a few
horseflies, too. The Fireflies were on the upper deck,
and the horseflies were on the Fireflies."
Duck Soup
95
next prev parent reply other threads:[~2020-05-01 10:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-01 4:51 What is the history behind Natural'First = 0 ? reinert
2020-05-01 7:52 ` J-P. Rosen
2020-05-01 8:38 ` AdaMagica
2020-05-01 10:24 ` J-P. Rosen
2020-05-01 19:03 ` Keith Thompson
2020-05-01 21:36 ` Robert A Duff
2020-05-03 20:08 ` Keith Thompson
2020-05-04 3:02 ` Keith Thompson
2020-05-04 8:50 ` Paul Rubin
2020-05-04 14:22 ` Dennis Lee Bieber
2020-05-01 10:13 ` Jeffrey R. Carter [this message]
2020-05-01 18:14 ` Optikos
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