....rotating intersections, freaky pattern dots....not to mention a 'saddle' number....and that is all before you start to apply it to 'real life' conditions, dazzlenation....and yes, this is a bit of a 'cheat sheet' isn't it?...although if you haven't done the maths, beforehand....in order to get to this stage....this 'shorthand' let us say....go figure:

Steve Phelps – Resources – GeoGebra

oh and then there's 'no', in relation to puzzle 7....lol....go figure:

Puzzle 7 – GeoGebra