Mimicking the spacing of DeclareMathOperator

Question

I would like to mimic the spacing behavior of DeclareMathOperator without using a macro. I would like there to be a space after Spec when I write (in math mode)

\mathrm{Spec} k.

But I would like there to be no space after Spec when I write

\mathrm{Spec} (k).

Is there a way to do this? Sort of like \xspace but not in a macro.

\mathrm is okay, I would like to avoid defining my own macros though (or at least only define one, rather than one for every operator) — Matt Larson, Aug 10 '20 at 06:17
I guess \operatorname{Spec} would be the easy solution (assuming the ubiquitous amsmath), see https://tex.stackexchange.com/q/84302/35864 — moewe, Aug 10 '20 at 06:25
I've written something and learned that I'm not supposed to define my own macros, so I need to change all the \Spec's to something. — Matt Larson, Aug 10 '20 at 15:02

Donald Arseneau · Accepted Answer · 2020-08-10T06:40:45.580

9

With amsmath package loaded

\[ \operatorname{Spec} k - \operatorname{Spec} (k) \]

or without amsmath

\[ \mathop{\mathrm{Spec}} k - \mathop{\mathrm{Spec}} (k) \]

If you ever want superscripts or subscripts with the primitive \mathop, you should add \nolimits

\[ \mathop{\mathrm{Spec}}\nolimits^2 k - \mathop{\mathrm{Spec}} (k^2) \]

edited Aug 10 '20 at 06:40

answered Aug 10 '20 at 06:26

Donald Arseneau

6,079

2

Punctuation *-/:' will also behave differently in \operatorname. – Henri Menke Aug 10 '20 at 07:10

Mimicking the spacing of DeclareMathOperator

1 Answers1