You mean using logical symbols such as A,B,C,D?. When you say possible do you mean merely conceivable, or merely logically possible? Point to any scientific article that demonstrates an ontologically possible path, and not just a metabolic pathway, but the required assemblage of parts. (The flagellum is not just a metabolic pathway.) If that happens, a design hypothesis for this nano outboard motor would be finished off, or at least rendered superfluous.
It does seem though that it is effectively impossible to falsify the Darwinian claim if that involves showing that there is NO conceivable Darwinian pathway by which a flagellum could have evolved, which would require proving a universal negative.
Cordially,
Why does Behe claim that he's done it then? Isn't one of the central thrusts of DBB that Behe claims that there is NO conceivable Darwinian pathway by which a flagellum could have evolved?
Showing that claim to be true - that there is no conceivable pathway by which the flagellum could have evolved - is not required in order to falsify the theory of evolution. Nevertheless, that is the claim that ID has chosen to advance. How unfortunate for them that they chose to advance a claim that requires them to prove a universal negative, as you insightfully point out.