The number line is a loop of wells

⊙ = re-entry · white pillar = 0 · dashed arrow = collapse · drag = rotate · shift-drag or right-drag = pan · scroll = zoom
0fixed pointrim = bottom84216 ≡ 49327 ≡ 9525 ≡ 5749 ≡ 711121 ≡ 116 = 2·315 = 3·510 = 2·5
0 closes the loop
0 is the fixed point of the number line, x = f(x). A fixed point of negation is true and false, and nothing explodes.
Primes (Brown)
Only re-enter at themselves: each prime opens its own well, and p⊙p lands back on it.
Powerset (Priest)
Re-entry is Inclosure: the closure is, and is not, among what it collects. That is the dashed return.
One landscape
Composites are not places on the line: 4, 8, 9 are depths in a well, 6, 10 and 15 are bridges between wells.