Opposites of functors between pretriangulated categories, #
If F : C ⥤ D is a functor between pretriangulated categories, we prove that
F is a triangulated functor if and only if F.op is a triangulated functor.
In order to do this, we first show that a CommShift structure on F naturally
gives one on F.op (for the shifts on Cᵒᵖ and Dᵒᵖ defined in
CategoryTheory.Triangulated.Opposite.Basic), and we then prove
that F.mapTriangle.op and F.op.mapTriangle correspond to each other via the
equivalences (Triangle C)ᵒᵖ ≌ Triangle Cᵒᵖ and (Triangle D)ᵒᵖ ≌ Triangle Dᵒᵖ
given by CategoryTheory.Pretriangulated.triangleOpEquivalence.
If F commutes with shifts, so does F.op, for the shifts chosen on Cᵒᵖ in
CategoryTheory.Triangulated.Opposite.Basic.
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Instances For
If F : C ⥤ D commutes with shifts, this expresses the compatibility of F.mapTriangle
with the equivalences Pretriangulated.triangleOpEquivalence on C and D.
Equations
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Instances For
If F : C ⥤ D commutes with shifts, this expresses the compatibility of F.mapTriangle
with the equivalences Pretriangulated.triangleOpEquivalence on C and D.
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Instances For
If F : C ⥤ D commutes with shifts, this is the 2-commutative square of categories
CategoryTheory.Functor.mapTriangleOpCompTriangleOpEquivalenceFunctor.
Vertical inverse of the 2-commutative square of
CategoryTheory.Functor.mapTriangleOpCompTriangleOpEquivalenceFunctor.
Equations
- One or more equations did not get rendered due to their size.
If F : C ⥤ D commutes with shifts, this expresses the compatibility of F.mapTriangle
with the equivalences Pretriangulated.triangleOpEquivalence on C and D.
Equations
- One or more equations did not get rendered due to their size.
Instances For
If F is triangulated, so is F.op.
If F.op is triangulated, so is F.
F is triangulated if and only if F.op is triangulated.