I wondered if Tom would include the streets that are long staircases, and, starting at the 10 minute point, he does. I have tried a "Manhattan nondeterministic

I wondered if Tom would include the streets that are long staircases, and, starting at the 10 minute point, he does. I have tried a "Manhattan nondeterministic run" a couple of times. The rules are simple: do not cross streets except where and when permitted by the crosswalk signs, and then you must cross. In practice, strict adherence to the "don't start crossing on flashing signs" rule leads to there being many times when you go around the same block more than once, and I am not suggesting one should do otherwise.