Each King can move along all eight congruent spirals. I had expected that to be clear from calling it a 'fully symmetric' spiral mover (and the earlier explanation that spiral moves are oblique and have 8 realizations). I have added a sentence now to make that more explicit.
Each King can move along all eight congruent spirals. I had expected that to be clear from calling it a 'fully symmetric' spiral mover (and the earlier explanation that spiral moves are oblique and have 8 realizations). I have added a sentence now to make that more explicit.