English
The map toInductiveLimit I n is an isometry (alternative formulation).
Русский
Отображение toInductiveLimit I n — изометрия (альтернативная формулировка).
LaTeX
$$$\text{Isometry}(\text{toInductiveLimit}(I,n))$$$
Lean4
/-- The map `toInductiveLimit n` mapping `X n` to the inductive limit is an isometry. -/
theorem toInductiveLimit_isometry (I : ∀ n, Isometry (f n)) (n : ℕ) : Isometry (toInductiveLimit I n) :=
Isometry.of_dist_eq fun x y => by
change inductiveLimitDist f ⟨n, x⟩ ⟨n, y⟩ = dist x y
rw [inductiveLimitDist_eq_dist I ⟨n, x⟩ ⟨n, y⟩ n (le_refl n) (le_refl n), leRecOn_self, leRecOn_self]