English
The opposite-level square relating mapTriangle and triangleOpEquivalence is coherent, yielding a commutative square up to isomorphism.
Русский
Противоположный квадрат между mapTriangle и triangleOpEquivalence совместим и приводится к согласованию посредством изоморфизма.
LaTeX
$$$F.op.mapTriangle \circ (triangleOpEquivalence C).inverse \cong (triangleOpEquivalence D).inverse \circ F.mapTriangle.op$$$
Lean4
/-- If `F` is triangulated, so is `F.op`.
-/
scoped instance functor_isTriangulated_op [F.IsTriangulated] : F.op.IsTriangulated where
map_distinguished T
dT := by
rw [mem_distTriang_op_iff]
exact
Pretriangulated.isomorphic_distinguished _ ((F.map_distinguished _ (unop_distinguished _ dT))) _
(((opMapTriangleCompTriangleOpEquivalenceInverse F).symm.app T).unop)