From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.4 required=5.0 tests=AC_FROM_MANY_DOTS,BAYES_00 autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,86d333341f490421 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2002-03-29 05:25:34 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!newsfeeds.belnet.be!news.belnet.be!psinet-eu-nl!psiuk-p4!uknet!psiuk-p3!uknet!psiuk-n!news.pace.co.uk!nh.pace.co.uk!not-for-mail From: "Marin David Condic" Newsgroups: comp.lang.ada Subject: Re: Natural data type ? Date: Thu, 28 Mar 2002 10:40:38 -0500 Organization: Posted on a server owned by Pace Micro Technology plc Message-ID: References: <3CA12AD4.2030807@oek.dk> <3CA25342.1080906@oek.dk> NNTP-Posting-Host: dhcp-200-133.miami.pace.co.uk X-Trace: nh.pace.co.uk 1017330038 22920 136.170.200.133 (28 Mar 2002 15:40:38 GMT) X-Complaints-To: newsmaster@news.cam.pace.co.uk NNTP-Posting-Date: 28 Mar 2002 15:40:38 GMT X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 Xref: archiver1.google.com comp.lang.ada:21829 Date: 2002-03-28T15:40:38+00:00 List-Id: In the end, its just a name. A rose by any other name would still give you sets with and without zero... :-) MDC -- Marin David Condic Senior Software Engineer Pace Micro Technology Americas www.pacemicro.com Enabling the digital revolution e-Mail: marin.condic@pacemicro.com "Chad R. Meiners" wrote in message news:a7u4as$ec8$1@msunews.cl.msu.edu... > I seriously doubt that someone made a random decision. There are many > reasons to define N to include zero, for instance, the positive integers can > easily represented as Z^+ while the negative integers may be represented as > Z^-. There is a very nice symmetry with these representations of disjoint > sets. It doesn't make sense to define the natural numbers to simply be the > set of positive integer because you then have two competing names for the > same set. Thus, it is better for the natural numbers (N) to be a different > set from the positive integers (Z^+). Since zero isn't positive, this > leaves N as the only candidate for containing zero. > > Very likely, whoever made this decision for Ada's data type of natural and > positive had a similar rational reason for making this choice. I just don't > see the designers flipping a coin or playing paper, scissors, rock to > determine which data type gets zero ;) I wasn't around during Ada's initial > design process; perhaps someone on comp.lang.ada was, and they know why or > who made this decision or even if the decision was contested. >