Inconsistent use of /can not/ and /cannot/ in dignostics


diagnostics messages have both "cannot" and "can not" forms. I think
we should choose one, and stick with it. Quick Google search suggests
that "cannot" is preferred. Do you have any objections to change "can
not" to "cannot"?



"can not" is often ambiguous -- "X can not Y" can mean either "it is not
the case that X is able to Y", or "X has the ability to not Y". In the
former case (which is probably the only case that occurs in our
diagnostics), I think we should use "cannot" to remove the ambiguity, and
in the latter case (if it occurs) we should rephrase to avoid "can not".