A week into the trip Korbel told me I was riding well, no trouble at all for him, so we would detour a little to the east, toward an oasis called Tongguzbasti. We would soon pick up a very old route, he told me, one that ran between the Khotan, which we had by then gained, and another riverbed, the Keriya. Along the way we would see something.

She took advantage of his desperation.

I was Dx'd with ADHD ten years ago.

Smoothness can vary from 0 (for a nondifferentiable function) to infinity (for a smooth function).