So not until the 101st revolution of the rear wheel does the bicycle return to the state ([theta] = 0, C = 0) where the chain falls off. During these hundred and one revolutions, Turing’s bicycle has proceeded for a distance of a fifth of a kilometer down the road, which is not too bad. So the bicycle is usable. However, unlike in the degenerate case, it is not possible for this bicycle to be placed in a state where the chain never falls off at all. This can be proved by going through the above list of values of C , and noticing that every possible value of C —every single number from 0 to 100—is on the list. What this means is that no matter what value C has when Turing begins to pedal, sooner or later it will work its way round to the fatal C = 0 and the chain will fall off. So Turing can leave his bicycle anywhere and be confident that, if stolen, it won’t go more than a fifth of a kilometer before the chain falls off.