What is the best/the usual way to typeset a placeholder for a variable in an equation?
Specifically, I want to do something like g = f(x, .) (which of course means that g is defined by g(y) = f(x,y)). I tried
\cdot, but it somehow does not look right (and the spacing needs to be adjusted either). On the other hand, a
\bullet seems to be too fat.
Any other suggestions?