It isn't ambiguous at all: Stop waffling.
Let me put it another way. Would you... No, I'll just repeat the question. In what way is it a "possibility"? Give details of your modal semantics.
For an example, cram this through your reasoning valve:
http://plato.stanford.edu/entries/logic-modal/#6 (Of course possible worlds semantics would be utterly duff for this case.)