Man, I can really see why arguing about this stuff produces lots of heat and little light. Sorry about not being very constructive. Yes, you're right - there's a decent way to translate "JTB" into probabilistic terms, which is to put a probability value on the T, assume that I B if my probability for a statement is above some threshold, and temporarily ignore the definition issues with J. Then you can assign a statement like KP the appropriate probability if my probability is above the threshold, and 0 if my probability is below the threshold.