# [OS X TeX] Latex symbol for "define equal"

Markus Klyver markusklyver at hotmail.com
Tue Aug 21 13:49:09 CEST 2018

```Definitions *are* equivalences.

________________________________
Från: MacOSX-TeX <macosx-tex-bounces at email.esm.psu.edu> för Ross Moore <ross.moore at mq.edu.au>
Skickat: den 21 augusti 2018 13:21
Till: TeX on Mac OS X Mailing List
Kopia: TeX on Mac OS X Mailing List
Ämne: Re: [OS X TeX] Latex symbol for "define equal"

Hi all.

I agree with using "when", or better "precisely when", in definitions.
Do not use these words in theorems. There are many alternative ways to express what you want.

In that context, equivalence is *not* the word you want for a definition, as equivalence depends on a particular relation, so is weaker than a definition.

There are nuances in mathematical concepts and notations that are not always correctly appreciated by those who work primarily in other (mostly applied) fields.

On 21/08/2018, at 13:03, "Markus Klyver" <markusklyver at hotmail.com<mailto:markusklyver at hotmail.com>> wrote:

But how would the reader know if it's a theorem or a definition? Consider the statement "f(x)=1 when x=2". Do we mean f(x)=1 <---> x=2 or just f(x)=1 <--- x=2?

________________________________
Från: MacOSX-TeX <macosx-tex-bounces at email.esm.psu.edu<mailto:macosx-tex-bounces at email.esm.psu.edu>> för Josep Maria Font <jmfont at ub.edu<mailto:jmfont at ub.edu>>
Skickat: den 21 augusti 2018 12:15
Till: TeX on Mac OS X Mailing List
Ämne: Re: [OS X TeX] Latex symbol for "define equal"

That's why I prefer to use "when" for definitions: [...this NEW thing happens...] WHEN [...such-and-such known, understandable condition holds...].

JMaF

Cheers,

Ross
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://tug.org/pipermail/macostex-archives/attachments/20180821/1ee9e03b/attachment.html>
-------------- next part --------------
----------- Please Consult the Following Before Posting -----------
TeX FAQ: http://www.tex.ac.uk/faq
List Reminders and Etiquette: https://sites.esm.psu.edu/~gray/tex/
List Archives: http://dir.gmane.org/gmane.comp.tex.macosx
https://email.esm.psu.edu/pipermail/macosx-tex/
TeX on Mac OS X Website: http://mactex-wiki.tug.org/
List Info: https://email.esm.psu.edu/mailman/listinfo/macosx-tex
```