The text of a question had already been edited, but the title needed editing too. I couldn't do this, except via the "improve edit" function. But then my edit was rejected as too insubstantial (even though it was necessary for the question to make sense). What is the way round this?
In response to a request, here is a link to the post concerned. (What is needed is a pair of parentheses around the argument of the limit, as is correctly done in the text of the question.)