Pullback symbol of morphisms?

Question

How can I get something like this:

which was meant to be the symbol for the pullback by the morphisms $s$ and $t$ .

It is meant to be used inline in math mode. It should be like x which we get by using \times.

My first effort was _{s} \times_t but there was much space between the $s$ and the \times.

Thanks.

Are there any limitations with this request? Do you want to use it in inline text and/or math, or just as a graphic? If you want inline usage, how would this affect the line-height? If used in inline math, will this be used in powers as well (and therefore need to size based on usage/location? Is the size of the cross the same as that of an X? Please be specific in your request. — Werner, Apr 22 '16 at 12:44

score 3 · Accepted Answer · edited Apr 13 '17 at 12:34

3

With reference to Left and right subscript / superscript, I'd suggest

\documentclass{article}

\newcommand{\pullback}[2]{{}_{#1}\kern-\scriptspace{\times}_{#2}}

\begin{document}

See $\pullback{s}{t}$ and then some \ldots

\end{document}

Using {\times} removes the spacing around \times, thereby changing it from an operator to an ordinary symbol. Minor spacing adjustment around scripted symbols provides the desired layout.

edited Apr 13 '17 at 12:34

Community

1

answered Apr 22 '16 at 13:10

Werner

603,163

The s and t are not equally spaced and it does not look nice when you write something before and after it, the spacing gets messed up. Anyway, I appreciate your help. – Dion Apr 22 '16 at 13:52
1

{}_{#1}\kern-\scriptspace{\times}_{#2} – egreg Apr 22 '16 at 15:24
1

And, looking more closely to the question, you should add \mathbin around the thing. – egreg Apr 22 '16 at 16:31
@Dion: Will the symbol be used as an operator between two other elements? – Werner Apr 22 '16 at 17:06
Now it seems nice =) Yep, I want to write things like $A s_\times_t B$.. – Dion Apr 22 '16 at 18:31
@Dion: Then you may be interested in \newcommand{\pullback}[2]{\mathbin{...}}. – Werner Apr 22 '16 at 18:33

Pullback symbol of morphisms?

1 Answers1