# How can I use German umlauts in DeclareMathOperator?

I would like to define a math operator Homöo, but when I try

\DeclareMathOperator{\Homoo}{Homöo}
\DeclareMathOperator{\Homoo}{Hom\"oo}


I get Homo.

How can I use German umlauts in DeclareMathOperator?

(If it's not possible at all: What should I do instead?)

## 1 Answer

The text in the second argument of \DeclareMathOperator is typeset in a special variety of \mathrm, so - produce a hyphen, for instance, not a minus sign. Fragments of words like yours can be dealt with by saying

\DeclareMathOperator{\Homoo}{\textnormal{Homöo}}


assuming a non fancy setup for fonts.

• @moose Moreover, you should use \textnormal if you need kerning in the operator. I recently needed it for the variance to get correct kerning between V and a: \DeclareMathOperator{\Var}{\textnormal{Var}}. – Manuel Jan 13 '14 at 23:27
• @Manuel: Thank you for the hint. When do I not need kerning in the operator? (For everybody who has to look up kerning: Wiki-article about kerning, one example) – Martin Thoma Jan 14 '14 at 6:22
• @moose I just wrote an example, if you use \DeclareMathOperator{\Var}{Var} and compare it with the one I used, you will see the difference, the V letter has space under it to put the lowercase a. There is no general rule for kerning, you need it when two letters can be kerned. – Manuel Jan 14 '14 at 11:17
• @Manuel, I was asking the other way around: Is there any reason not to use \textnormal? – Martin Thoma Jan 14 '14 at 12:24
• @Manuel I get no difference between \operatorname{Var} and \operatorname{\textnormal{Var}} – egreg Jan 14 '14 at 12:34