Sorry, the chain is just Set Theory Natural Numbers Integers Rationals Real Numbers Complex Numbers Calculus Riemann Surfaces (as the Apple ads say, some step

Sorry, the chain is just Set Theory Natural Numbers Integers Rationals Real Numbers Complex Numbers Calculus Riemann Surfaces (as the Apple ads say, some steps skipped) The only point I was making was that the level you were thinking at was much higher than the level SEXPs are at. Trying to envisage how we get there remains hard. TL;DR I was agreeing with you. :)