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
.
Equations
- One or more equations did not get rendered due to their size.
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
- One or more equations did not get rendered due to their size.
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
- One or more equations did not get rendered due to their size.
Instances For
If F : C ⥤ D
commutes with shifts, this is the 2-commutative square of categories
CategoryTheory.Functor.mapTriangleOpCompTriangleOpEquivalenceFunctor
.
Equations
- F.instCatCommSqOppositeTriangleOpMapTriangleFunctorTriangleOpEquivalence = { iso' := F.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.