Registry · Definition II.D18 established formalized

II.D18 — Pinch Map

The surjection p: T^2 -> L collapsing the diagonal circle to the wedge point. The canonical degeneration of torus to lemniscate.

Book II Part 3 Ch. 17

Dependency Graph

Depends on (2)

II.D06 I.D18

Depended on by (1)

II.T14

Lean Formalization

Module: TauLib.BookII.Topology.TorusDegeneration

Symbol: pinch_fiber