Differences Between Theorems Modules (AMS and non AMS)

[Richard Kimberly Heck]

On 9/15/22 09:11, Jean-Marc Lasgouttes wrote:
> Le 14/09/2022 à 02:28, Udicoudco a écrit :
>> Hello Lyx Developers,
>>
>> Recently I've been trying to understand more thoroughly how theorems 
>> modules are implemented in LyX, and I think I've come across some 
>> bugs, and some redundant modules (but I might have misunderstood a 
>> few things).
>
> Hello Udi,
>
> Thanks for looking at that.
>
>> The first thing I've noticed is that all AMS theorems related modules 
>> load the packages amsmath and amsthm even if the use did not use any 
>> layout.  I could not understand why, as amsthm does not depend on 
>> amsmath.  I've tried to compile a lyx file containing all the layouts 
>> defined in Theorem (AMS), but i erased the line "Require 
>> amsmath,amsthm" from the module, and the file compiled (as amsthm is 
>> loaded by the layouts, there is no really a need to load the package 
>> if the user did not use any layout).
>
> This looks like a bug indeed.

These have gone through so many versions, that I'm not surprised bugs 
have accumulated over the years. Cleaning it all up is a great idea.


>
>> The second thing I've noticed, there is no difference between the 
>> files theorems.inc and theorems-ams.inc. In the description of the 
>> file theorems-std.module, which uses theorems.inc it is said that the 
>> module "Defines some theorem environments for use with non-AMS 
>> classes", but the module uses amsthm, and he is compilable with AMS 
>> classes.
>
> This is indeed surprising. In the old days, non-ams theorem modules 
> did not use amsthm. But for some reason it was changed when 
> modularizing the layouts. I am not sure whether we can revert this 
> decision 14 years later (see below). If we don't, the two types of 
> theorems should be merged indeed.
>
> The culprit is:
>
> commit f5a5be4d188a20ee2a5c0213ee11bf64c0908841
> Author: Richard Heck <rgheck at comcast.net>
> Date:   Thu Jan 10 04:58:20 2008 +0000
>
>     Modularization of the AMS classes, and the theorem environments 
> generally.
>
>     This is Part I: The changes to the layout files and modules. Part 
> II, still
>     to come, will involve lyx2lyx to help people who were using the 
> older classes.

I'm guessing I failed to notice this similarity. That was a while ago!

Riki


-- 
----------------------------
Richard Kimberly (Riki) Heck
Professor of Philosophy
Brown University

Pronouns: they/them/their

Website:         http://rkheck.frege.org/
Blog:            http://rikiheck.blogspot.com/
Amazon:          http://amazon.com/author/richardgheckjr
Google Scholar:  https://scholar.google.com/citations?user=QUKBG6EAAAAJ
ORCID:           http://orcid.org/0000-0002-2961-2663
Research Gate:   https://www.researchgate.net/profile/Richard_Heck