> Without demand, the test for pricing power (the ability to raise prices from some level at which there are nonzero sales without losing sales) cannot be satisfied -- you can't have market power with no market.

In theory that's the test, but it doesn't actually work. In practice market power isn't binary. There is always a substitute for anything if you jack the price up high enough. And a monopolist would jack the price right up to that point, so that increasing it any more would cost sales.

But the zero volume case is the divide by zero case anyway. A test isn't going to give you a yes or no, it's going to give you NaN. That doesn't mean there is no market power, it only means you can't tell without a buyer. And in the patent case, as soon as there is a buyer there is market power.