I have to type the product of n variables,
Although maybe this is semantically the right way (like it is for the sum), it doesn't look very well. What should be, typographically, a better way to do it?
Just the ldots as in
$x_1\ldots x_n$ is confusing when there are going to be also lists of the variables separated by commas in nearby sentences.
\dotsc like in
$x_1\dotsc x_n$ maybe, but is there a better idea?