Path: utzoo!attcan!uunet!husc6!bloom-beacon!mit-eddie!bbn!rochester!pt.cs.cmu.edu!sei!dd
From: dd@sei.cmu.edu (Dennis Doubleday)
Newsgroups: comp.lang.ada
Subject: Re: Type NATURAL isn't
Message-ID: <2937@fi.sei.cmu.edu>
Date: 24 Jun 88 14:45:35 GMT
References: <8806231808.AA15365@spp3.SPP>
Reply-To: dd@sei.cmu.edu (Dennis Doubleday)
Organization: Software Engineering Institute, Pittsburgh, PA
Lines: 23

In article <8806231808.AA15365@spp3.SPP> simpson@spp3.UUCP (Scott Simpson) writes:
>Can anybody explain why the LRM declares NATURAL as
>    
>    subtype NATURAL is INTEGER range 0..INTEGER'LAST;
>
>Natural numbers start at 1!  Any mathematician would assume it
>to be the same declaration as POSITIVE.

I've never heard this before.  The first two books I took off my
bookshelf both define the set N of natural numbers as
{0,1,2,3...}.  These books are "Computability, Complexity, and
Languages" by Martin D. Davis and Elaine J. Weyuker, and "Discrete
Mathemetical Structures with Applications to Computer Science" by J.P.
Tremblay and R. Manohar.  Is there disagreement over the definition of
the set of natural numbers?



-- 
Dennis Doubleday                       dd@sei.cmu.edu
Software Engineering Institute         (412)268-5873
Carnegie Mellon University
Pittsburgh, PA 15213