Cartesian coordinates as a homeomorphism
DefinitionLeanFormalizations_PachDeZeeuw_ChartBridgetopology
This defines the coordinate homeomorphism from the two-dimensional real Euclidean space to the Cartesian product of two real lines.
Definition code
-- Extracted dependency interfaces and their necessary proofs. import Definitions.Def_LeanFormalizations_PachDeZeeuw_Bezout import Mathlib set_option autoImplicit true /- Copyright (c) 2026 Adam McKenna. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Adam McKenna -/ set_option linter.style.longLine false namespace PachDeZeeuw.Algebraic open scoped Topology noncomputable def chartEquiv : EuclideanSpace ℝ (Fin 2) ≃ₜ ℝ × ℝ := (EuclideanSpace.equiv (Fin 2) ℝ).toHomeomorph.trans Homeomorph.finTwoArrow scoped notation "E" => chartEquiv end PachDeZeeuw.Algebraic