The progression is natural (it also leads to "code golf", lambda calculus/SKI, etc.): almost everyone learns to ride vehicles with three wheels, most people lea

The progression is natural (it also leads to "code golf", lambda calculus/SKI, etc.): almost everyone learns to ride vehicles with three wheels, most people learn to ride vehicles with two, so why not continue the minimisation to one? (zero wheels would normally be considered too degenerate to be practical, but maybe some hacker may eventually come up with the pedal-powered hovercraft? How about fractional wheels [or is this just a penny farthing]? imaginary wheels?)