# DeclareMathOperator with capital Greek letter [closed]

So, I tried to do something like this

\DeclareMathOperator{\hs}{\Theta}


and I was quite surprised to find out, that this does not work (i.e., writing $\hs$ yields no output but no error message as well).

After a little testing I found that this is the case for all capital Greek letters, e.g. \DeclareMathOperator{\hs}{\lambda} works correctly and \hs gets compiled to a small lambda, while with \DeclareMathOperator{\hs}{\Lambda} the command \hs does not generate any output after compilation.

I worked my way through the documentation of amsopn, and I found in the definition of \DeclareMathOperator that the problem lies within the \operator@font command defined as

\def\operator@font{\mathgroup\symoperators}.


It seems that the problem lies within the \mathgroup macro. Sadly, I haven't found anything, which explains why something like \mathgroup\symoperators\Gamma does not work. And before I waste an entire day on this I rather ask you guys. Thanks in advance.

## EDIT

I'm using LuaLaTex.

## closed as unclear what you're asking by egreg, Mensch, user36296, Zarko, Stefan PinnowJan 8 '17 at 16:16

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• The snippet works fine for me. A full MWE may be helpful. – campa Dec 9 '16 at 12:16
• No problems here either. So as campa says, please provide something where we do not have to guess most of the document – daleif Dec 9 '16 at 12:23
• Yes, I should have created a MWE, this basically answered my own question.. It's probably the best, if we delete the question? – manthano Dec 9 '16 at 12:36
• I think there is no need to delete the question, but you should definitely update it (and your answer) as to make clear what the problem is (and what solution worked). – campa Dec 9 '16 at 12:46

Ok, the problem was the \operator@font command and the usage of LuaLaTeX without unicode-math. Including the package provided the necessary glyph.
Apparently, the small Greek letters aren't changed by \operator@font, while the capital letters are. Therefore this problem emerged.