Re: spurious space after macro expansion in math mode for TeX output

[Gavin Smith]

On Tue, Nov 08, 2022 at 11:27:08AM +0100, Vincent Lefevre wrote:
> On 2022-11-08 07:04:11 +0000, Gavin Smith wrote:
> > On Tue, Nov 08, 2022 at 03:57:48AM +0100, Vincent Lefevre wrote:
> > > Note that there is the same issue with a Texinfo macro, i.e. with
> > > 
> > > @iftex
> > > @macro atan
> > > \\mathop{\\rm atan}
> > > @end macro
> > > @end iftex
> > > 
> > > instead of the \gdef\atan{\mathop{\rm atan}}. This is even more
> > > unexpected, and this seems to be a Texinfo problem.
> > 
> > Yes, but it is unlikely that this can be fixed.
> 
> The manual doesn't say that this is forbidden or that wouldn't work
> as expected.

We don't document in the Texinfo manual how TeX math mode spacing works.
The spacing is as expected for TeX.

> So one would need to use something like @mysin{} (with a definition
> to expand it to "sin"). But it would be better for source readability
> and less confusing if either @math{@sin{}(x)} or @math{@sin(x)} were
> allowed.

Another idea: define @Sin so that you could do @math{@Sin{}(x)}.  With
the right definition you could also do @math{@Sin{x}}.