\rightarrow has math symbol class 3, that is, it is a math relation.
How can I define a macro, let's call it
\rightinf, to get the same right arrow character, but as an ordinary math symbol (like
\infty, say) rather than as a math relation?
Reason for the question:
I want to use
\rightinf to designate intervals in an ordered set that are not bounded above, as in
(0, \rightinf), instead of