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Re: Making 'eq' == 'eql' in bignum branch
From: |
Herring, Davis |
Subject: |
Re: Making 'eq' == 'eql' in bignum branch |
Date: |
Wed, 29 Aug 2018 03:42:26 +0000 |
> Such a name should make clear that we're talking about a signed
> infinity, not one that makes 1/x continuous by adding a point at
> infinity to the real line.
Sure: the extended reals
<https://en.wikipedia.org/wiki/Extended_real_number_line>, not the projective
reals <https://en.wikipedia.org/wiki/Projectively_extended_real_line>.
> Signed infinities are convenient symbols, but they're not numbers; I
> recall the horrified reaction of a mathematician when I told her about
> IEEE infinities (she thought I was making it up about NaNs).
Of course +/-inf are numbers. They're not real numbers, but neither are
complex numbers, split-complex numbers, dual numbers, p-adic numbers,
quaternions, octonions, sedenions, hyperreal numbers, or (please no) surreal
numbers. With all due respect to your mathematician friend, she has no
exclusive claim over the definition (such as it is) of "number" (and I'm a bit
surprised if she hadn't heard of at least one of the extended real lines I
linked).
NaN, on the other hand, is of course a floating-point value that explicitly
claims not to be a number. I'm not sure whether to believe it; it seems very
useful that the operations on floating-point "numbers" are closed, but that
depends on NaN being one of them...
Davis
- Re: Making 'eq' == 'eql' in bignum branch, (continued)
- Re: Making 'eq' == 'eql' in bignum branch, Stefan Monnier, 2018/08/28
- Re: Making 'eq' == 'eql' in bignum branch, Clément Pit-Claudel, 2018/08/29
- Re: Making 'eq' == 'eql' in bignum branch, Lars Ingebrigtsen, 2018/08/27
- Re: Making 'eq' == 'eql' in bignum branch, Pip Cet, 2018/08/27
- Re: Making 'eq' == 'eql' in bignum branch, Paul Eggert, 2018/08/27
- Re: Making 'eq' == 'eql' in bignum branch, Ken Raeburn, 2018/08/28
- Re: Making 'eq' == 'eql' in bignum branch, Helmut Eller, 2018/08/28
- Re: Making 'eq' == 'eql' in bignum branch, Stefan Monnier, 2018/08/28
- Re: Making 'eq' == 'eql' in bignum branch, Clément Pit-Claudel, 2018/08/28
- Re: Making 'eq' == 'eql' in bignum branch, Pip Cet, 2018/08/28
- Re: Making 'eq' == 'eql' in bignum branch,
Herring, Davis <=
- Re: Making 'eq' == 'eql' in bignum branch, Helmut Eller, 2018/08/29
- Re: Making 'eq' == 'eql' in bignum branch, Pip Cet, 2018/08/29
- Re: Making 'eq' == 'eql' in bignum branch, Alan Mackenzie, 2018/08/31
- Re: Making 'eq' == 'eql' in bignum branch, Clément Pit-Claudel, 2018/08/31
- Re: Making 'eq' == 'eql' in bignum branch, Alan Mackenzie, 2018/08/31
- Re: Making 'eq' == 'eql' in bignum branch, Herring, Davis, 2018/08/31
- Re: Making 'eq' == 'eql' in bignum branch, Stefan Monnier, 2018/08/31
- Re: Making 'eq' == 'eql' in bignum branch, Herring, Davis, 2018/08/31
- Re: Making 'eq' == 'eql' in bignum branch, Elias Mårtenson, 2018/08/28
- Re: Making 'eq' == 'eql' in bignum branch, Clément Pit-Claudel, 2018/08/29