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From: Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups: comp.theory
Subject: Re: Real Number --- Merely numbers whose digits can be infinitely long
Date: Mon, 29 Apr 2024 22:02:21 -0700
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wij <wyniijj5@gmail.com> writes:
[...]
> Got your idea. I'll try use '|' exclusively. Thanks for the suggestions:
>
>      <fixed_point_number>::= [-] <wnum> [ . <frac> ]  // excluding "-0" case
>      <wnum>::= 0
>      <wnum>::= <nzd> { 0 | <nzd> }
>      <frac>::= { 0 | <nzd> } <nzd>
>      <nzd> ::= 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 // 'digit' varys depending on n-ary
>
>     Ex: 78, -12.345, 3.1414159

Am I correct in assuming that this is intended to match only finite
strings?  (The fact that <nzd>, non-zero digit, appears at the end of
<frac> seems to imply that there must be an end.)

If so, your <fixed_point_number> can only represent integer multiples of
powers of 10 (or of the base if you allow bases other than decimal).

Is 1/3 not a fixed-point number?

Your subject line refers to *real* numbers; is π not a real number in
your view?

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Medtronic
void Void(void) { Void(); } /* The recursive call of the void */