English
HasPointwiseRightKanExtensionAt is invariant under a natural isomorphism between L and L'.
Русский
HasPointwiseRightKanExtensionAt сохраняет инвариантность при натуральной изоморфности между L и L'.
LaTeX
$$$HasPointwiseRightKanExtensionAt\\ L F Y \\iff HasPointwiseRightKanExtensionAt\\ L' F Y$$$
Lean4
theorem hasPointwiseRightKanExtensionAt_iff_of_iso {Y₁ Y₂ : D} (e : Y₁ ≅ Y₂) :
HasPointwiseRightKanExtensionAt L F Y₁ ↔ HasPointwiseRightKanExtensionAt L F Y₂ :=
by
revert Y₁ Y₂ e
suffices ∀ ⦃Y₁ Y₂ : D⦄ (_ : Y₁ ≅ Y₂) [HasPointwiseRightKanExtensionAt L F Y₁], HasPointwiseRightKanExtensionAt L F Y₂
from fun Y₁ Y₂ e => ⟨fun _ => this e, fun _ => this e.symm⟩
intro Y₁ Y₂ e _
change HasLimit ((StructuredArrow.mapIso e.symm).functor ⋙ StructuredArrow.proj Y₁ L ⋙ F)
infer_instance