In math editor, how do I escape keywords?

In math markup, I’d like to write something like:

%alpha ^{sup} + %alpha ^ {inf}

Obviously this does not work because “sup” is a keyword. Escaping it with double quotes makes the rendering different (literal) , and even with the “ital” keyword in front of it, the result is not conclusive. Is there a way to tell math that the following text is literal but still a symbol?

By the way, writing "sup in the graphical editor seems to work until you try to reedit the formula, which is kind of tricky.

What you write here isn’t mathml.

Ah, sorry, this is LO math markup. Will edit the question.

A workaround is using uoper:

%alpha ^{uoper sup {}} + %alpha ^ {inf}

That works!

%alpha ^{ital "sup"} + %alpha ^{ital "inf"}