Re: DeclareMathOperator and digit in operator name

On 2025-12-17 21:42:31 +0100, Zdenek Wagner wrote:
> st 17. 12. 2025 v 16:15 odesílatel Vincent Lefevre <[email protected]> napsal:
> >
> > On 2025-12-17 14:53:50 +0000, Ji Luo wrote:
> > > An easier hotfix is
> > >
> > > \DeclareMathOperator{\myFast}{whatever}
> > > \def\Fast2Sum{\myFast}
> >
> > Thanks. Actually, just adding
> >
> > \def\Fast2Sum{\FastTwoSum}
> >
> > *before* the existing
> >
> > \DeclareMathOperator{\Fast2Sum}{Fast2Sum}
> >
> This is not a good solution. If you later define
> \def\Fast3Sum{\FastThreeSum}
> \Fast2Sum will cause an error because you redefined \Fast to require 3Sum.

The only goal is to easily modify old LaTeX code so that it can be
compiled. Except from that, such a code will not be modified.

The only issue is if one had

\DeclareMathOperator{\Fast2Sum}{Fast2Sum}
\DeclareMathOperator{\Fast3Sum}{Fast3Sum}

But I could check with texlive 2022.20230122-3 (Debian bookworm)
that this wasn't working:

! Use of \Fast doesn't match its definition.
l.6 $\Fast2
           Sum(X)$

so that we would have detected the buggy code and fixed it.

-- 
Vincent Lefèvre <[email protected]> - Web: <https://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / Pascaline project (LIP, ENS-Lyon)