English
If F preserves shifts, the constructed isomorphism mapTriangleOpCompTriangleOpEquivalenceFunctorApp exhibits a natural isomorphism between the composite functors F.mapTriangle.op and triangleOpEquivalence composed with F.op.mapTriangle.
Русский
Если F сохраняет сдвиги, построенный изоморфизм mapTriangleOpCompTriangleOpEquivalenceFunctorApp образует естественный изоморфизм между сочетанием F.mapTriangle.op и triangleOpEquivalence ∘ F.op.mapTriangle.
LaTeX
$$$(triangleOpEquivalence D).functor \circ F.mapTriangle \cong F.op.mapTriangle \circ (triangleOpEquivalence C).functor$$$
Lean4
theorem isomorphic_distinguished (T₁ : Triangle Cᵒᵖ) (hT₁ : T₁ ∈ distinguishedTriangles C) (T₂ : Triangle Cᵒᵖ)
(e : T₂ ≅ T₁) : T₂ ∈ distinguishedTriangles C :=
by
simp only [mem_distinguishedTriangles_iff] at hT₁ ⊢
exact Pretriangulated.isomorphic_distinguished _ hT₁ _ ((triangleOpEquivalence C).inverse.mapIso e).unop.symm