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Subject: What is the history behind Natural'First = 0 ?
From: reinert <reinkor@gmail.com>
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Xref: reader01.eternal-september.org comp.lang.ada:58535
Date: 2020-04-30T21:51:07-07:00
List-Id: <comp.lang.ada>

I have been wondering about this for years:

Why Natural'First =3D 0 ?

There is no consensus about including 0 among the natural numbers.
Since there is a Positive (Positive'First =3D 1), one may expect Natural'Fi=
rst =3D 0
Except for this, I find little intuition in "Natural'First =3D 0".


Copy form: https://en.wikipedia.org/wiki/Natural_number#History

Some definitions, including the standard ISO 80000-2,[1][2] begin the natur=
al numbers with 0, corresponding to the non-negative integers 0, 1, 2, 3, =
=E2=80=A6, whereas others start with 1, corresponding to the positive integ=
ers 1, 2, 3, =E2=80=A6,[3][4] while others acknowledge both definitions.[5]=
 Texts that exclude zero from the natural numbers sometimes refer to the na=
tural numbers together with zero as the whole numbers, but in other writing=
s, that term is used instead for the integers (including negative integers)=
.[6]

Is the key point here: "the standard ISO 80000-2" ?

reinert