English
There is an isomorphism between the Karoubi-quotiented nondegenerate complex and the N₁.obj X object, compatible with the simplicial structure.
Русский
Существует изоморфизм между каруоби-обработанным некондиционным комплексом и объектом N₁.obj X, совместимый со структурой простейшального объекта.
LaTeX
$$(toKaroubi _).obj s.nondegComplex ≅ N₁.obj X$$
Lean4
theorem simply_connected_iff_unique_homotopic (X : Type*) [TopologicalSpace X] :
SimplyConnectedSpace X ↔ Nonempty X ∧ ∀ x y : X, Nonempty (Unique (Path.Homotopic.Quotient x y)) :=
by
simp only [simply_connected_def, equiv_punit_iff_unique, FundamentalGroupoid.nonempty_iff X, and_congr_right_iff,
Nonempty.forall]
intros
exact ⟨fun h _ _ => h _ _, fun h _ _ => h _ _⟩