If it is not impossible (therefore possible) - then it is terribly difficult.
No doubt about it But what I wanted to know the correct grammar for "it is difficult (or maybe even impossible)" in the kind of form I used in the original post (assuming it can be used at all).
i would suggest either
"it is difficult (if possible)" "it is difficult (or impossible)"
_________________ Win•dows: n. A thirty-two bit extension and graphical shell to a sixteen-bit patch to an eight-bit operating system originally coded for a four-bit microprocessor which was written by a two-bit company that can't stand one bit of competition.