Re: DeclareMathOperator and digit in operator name

An easier hotfix is

\DeclareMathOperator{\myFast}{whatever}
\def\Fast2Sum{\myFast}

But of course avoiding numbers in csname is the sustainable way to go.

________________________________
From: tex-live <[email protected]> on behalf of Vincent Lefevre <[email protected]>
Sent: Wednesday, December 17, 2025 9:49:59 AM
To: [email protected] <[email protected]>
Subject: Re: DeclareMathOperator and digit in operator name

On 2025-12-17 14:39:00 +0000, Joseph Wright wrote:
> On 17/12/2025 14:32, Vincent Lefevre wrote:
[...]
> > \DeclareMathOperator{\Fast2Sum}{Fast2Sum}
>
> This was never supported: you are defining \Fast to *require* being
> followed by "2Sum".

OK, thanks for the explanation.

> There were technical changes which mean the path taken may change,
> but as this was always an error, the outcome is not something that
> is 'controlled'.

The main issue is that no errors were generated before, so that old
LaTeX files can now no longer be compiled. However, preprocessing
to change the operator name could be sufficient.

--
Vincent Lefèvre <[email protected]> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / Pascaline project (LIP, ENS-Lyon)