Simplicial objects in a category. #
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A simplicial object in a category C
is a C
-valued presheaf on simplex_category
.
(Similarly a cosimplicial object is functor simplex_category ⥤ C
.)
Use the notation X _[n]
in the simplicial
locale to obtain the n
-th term of a
(co)simplicial object X
, where n
is a natural number.
The category of simplicial objects valued in a category C
.
This is the category of contravariant functors from simplex_category
to C
.
Equations
Instances for category_theory.simplicial_object
- category_theory.simplicial_object.category
- category_theory.simplicial_object.category_theory.limits.has_limits_of_shape
- category_theory.simplicial_object.category_theory.limits.has_limits
- category_theory.simplicial_object.category_theory.limits.has_colimits_of_shape
- category_theory.simplicial_object.category_theory.limits.has_colimits
- category_theory.idempotents.category_theory.simplicial_object.category_theory.is_idempotent_complete
Face maps for a simplicial object.
Equations
- X.δ i = X.map (simplex_category.δ i).op
Degeneracy maps for a simplicial object.
Equations
- X.σ i = X.map (simplex_category.σ i).op
Isomorphisms from identities in ℕ.
Equations
The generic case of the first simplicial identity
The special case of the first simplicial identity
The second simplicial identity
The first part of the third simplicial identity
The second part of the third simplicial identity
The fourth simplicial identity
The fifth simplicial identity
Functor composition induces a functor on simplicial objects.
Truncated simplicial objects.
Equations
Instances for category_theory.simplicial_object.truncated
- category_theory.simplicial_object.truncated.category
- category_theory.simplicial_object.truncated.category_theory.limits.has_limits_of_shape
- category_theory.simplicial_object.truncated.category_theory.limits.has_limits
- category_theory.simplicial_object.truncated.category_theory.limits.has_colimits_of_shape
- category_theory.simplicial_object.truncated.category_theory.limits.has_colimits
Functor composition induces a functor on truncated simplicial objects.
The skeleton functor from simplicial objects to truncated simplicial objects.
The constant simplicial object is the constant functor.
The category of augmented simplicial objects, defined as a comma category.
Equations
Instances for category_theory.simplicial_object.augmented
Drop the augmentation.
The point of the augmentation.
The functor from augmented objects to arrows.
Equations
- category_theory.simplicial_object.augmented.to_arrow = {obj := λ (X : category_theory.simplicial_object.augmented C), {left := (category_theory.simplicial_object.augmented.drop.obj X).obj (opposite.op (simplex_category.mk 0)), right := category_theory.simplicial_object.augmented.point.obj X, hom := X.hom.app (opposite.op (simplex_category.mk 0))}, map := λ (X Y : category_theory.simplicial_object.augmented C) (η : X ⟶ Y), {left := (category_theory.simplicial_object.augmented.drop.map η).app (opposite.op (simplex_category.mk 0)), right := category_theory.simplicial_object.augmented.point.map η, w' := _}, map_id' := _, map_comp' := _}
The compatibility of a morphism with the augmentation, on 0-simplices
Functor composition induces a functor on augmented simplicial objects.
Equations
- category_theory.simplicial_object.augmented.whiskering_obj C D F = {obj := λ (X : category_theory.simplicial_object.augmented C), {left := ((category_theory.simplicial_object.whiskering C D).obj F).obj (category_theory.simplicial_object.augmented.drop.obj X), right := F.obj (category_theory.simplicial_object.augmented.point.obj X), hom := category_theory.whisker_right X.hom F ≫ (category_theory.functor.const_comp simplex_categoryᵒᵖ X.right F).hom}, map := λ (X Y : category_theory.simplicial_object.augmented C) (η : X ⟶ Y), {left := category_theory.whisker_right η.left F, right := F.map η.right, w' := _}, map_id' := _, map_comp' := _}
Functor composition induces a functor on augmented simplicial objects.
Equations
- category_theory.simplicial_object.augmented.whiskering C D = {obj := category_theory.simplicial_object.augmented.whiskering_obj C D _inst_2, map := λ (X Y : C ⥤ D) (η : X ⟶ Y), {app := λ (A : category_theory.simplicial_object.augmented C), {left := category_theory.whisker_left (category_theory.simplicial_object.augmented.drop.obj A) η, right := η.app (category_theory.simplicial_object.augmented.point.obj A), w' := _}, naturality' := _}, map_id' := _, map_comp' := _}
Augment a simplicial object with an object.
Cosimplicial objects.
Equations
Instances for category_theory.cosimplicial_object
- category_theory.cosimplicial_object.category
- category_theory.cosimplicial_object.category_theory.limits.has_limits_of_shape
- category_theory.cosimplicial_object.category_theory.limits.has_limits
- category_theory.cosimplicial_object.category_theory.limits.has_colimits_of_shape
- category_theory.cosimplicial_object.category_theory.limits.has_colimits
- category_theory.idempotents.category_theory.cosimplicial_object.category_theory.is_idempotent_complete
Coface maps for a cosimplicial object.
Equations
- X.δ i = X.map (simplex_category.δ i)
Codegeneracy maps for a cosimplicial object.
Equations
- X.σ i = X.map (simplex_category.σ i)
Isomorphisms from identities in ℕ.
Equations
The generic case of the first cosimplicial identity
The special case of the first cosimplicial identity
The second cosimplicial identity
The first part of the third cosimplicial identity
The second part of the third cosimplicial identity
The fourth cosimplicial identity
The fifth cosimplicial identity
Functor composition induces a functor on cosimplicial objects.
Truncated cosimplicial objects.
Equations
Instances for category_theory.cosimplicial_object.truncated
- category_theory.cosimplicial_object.truncated.category
- category_theory.cosimplicial_object.truncated.category_theory.limits.has_limits_of_shape
- category_theory.cosimplicial_object.truncated.category_theory.limits.has_limits
- category_theory.cosimplicial_object.truncated.category_theory.limits.has_colimits_of_shape
- category_theory.cosimplicial_object.truncated.category_theory.limits.has_colimits
Functor composition induces a functor on truncated cosimplicial objects.
The skeleton functor from cosimplicial objects to truncated cosimplicial objects.
The constant cosimplicial object.
Augmented cosimplicial objects.
Equations
Instances for category_theory.cosimplicial_object.augmented
Drop the augmentation.
The point of the augmentation.
The functor from augmented objects to arrows.
Equations
- category_theory.cosimplicial_object.augmented.to_arrow = {obj := λ (X : category_theory.cosimplicial_object.augmented C), {left := category_theory.cosimplicial_object.augmented.point.obj X, right := (category_theory.cosimplicial_object.augmented.drop.obj X).obj (simplex_category.mk 0), hom := X.hom.app (simplex_category.mk 0)}, map := λ (X Y : category_theory.cosimplicial_object.augmented C) (η : X ⟶ Y), {left := category_theory.cosimplicial_object.augmented.point.map η, right := (category_theory.cosimplicial_object.augmented.drop.map η).app (simplex_category.mk 0), w' := _}, map_id' := _, map_comp' := _}
Functor composition induces a functor on augmented cosimplicial objects.
Equations
- category_theory.cosimplicial_object.augmented.whiskering_obj C D F = {obj := λ (X : category_theory.cosimplicial_object.augmented C), {left := F.obj (category_theory.cosimplicial_object.augmented.point.obj X), right := ((category_theory.cosimplicial_object.whiskering C D).obj F).obj (category_theory.cosimplicial_object.augmented.drop.obj X), hom := (category_theory.functor.const_comp simplex_category (category_theory.cosimplicial_object.augmented.point.obj X) F).inv ≫ category_theory.whisker_right X.hom F}, map := λ (X Y : category_theory.cosimplicial_object.augmented C) (η : X ⟶ Y), {left := F.map η.left, right := category_theory.whisker_right η.right F, w' := _}, map_id' := _, map_comp' := _}
Functor composition induces a functor on augmented cosimplicial objects.
Equations
- category_theory.cosimplicial_object.augmented.whiskering C D = {obj := category_theory.cosimplicial_object.augmented.whiskering_obj C D _inst_2, map := λ (X Y : C ⥤ D) (η : X ⟶ Y), {app := λ (A : category_theory.cosimplicial_object.augmented C), {left := η.app (category_theory.cosimplicial_object.augmented.point.obj A), right := category_theory.whisker_left (category_theory.cosimplicial_object.augmented.drop.obj A) η, w' := _}, naturality' := _}, map_id' := _, map_comp' := _}
Augment a cosimplicial object with an object.
The anti-equivalence between simplicial objects and cosimplicial objects.
The anti-equivalence between cosimplicial objects and simplicial objects.
Construct an augmented cosimplicial object in the opposite category from an augmented simplicial object.
Equations
- X.right_op = {left := opposite.op X.right, right := category_theory.functor.right_op X.left, hom := category_theory.nat_trans.right_op X.hom}
Construct an augmented simplicial object from an augmented cosimplicial object in the opposite category.
Equations
- X.left_op = {left := category_theory.functor.left_op X.right, right := opposite.unop X.left, hom := category_theory.nat_trans.left_op X.hom}
Converting an augmented simplicial object to an augmented cosimplicial object and back is isomorphic to the given object.
Converting an augmented cosimplicial object to an augmented simplicial object and back is isomorphic to the given object.
A functorial version of simplicial_object.augmented.right_op
.
Equations
- category_theory.simplicial_to_cosimplicial_augmented C = {obj := λ (X : (category_theory.simplicial_object.augmented C)ᵒᵖ), (opposite.unop X).right_op, map := λ (X Y : (category_theory.simplicial_object.augmented C)ᵒᵖ) (f : X ⟶ Y), {left := f.unop.right.op, right := category_theory.nat_trans.right_op f.unop.left, w' := _}, map_id' := _, map_comp' := _}
A functorial version of cosimplicial_object.augmented.left_op
.
Equations
- category_theory.cosimplicial_to_simplicial_augmented C = {obj := λ (X : category_theory.cosimplicial_object.augmented Cᵒᵖ), opposite.op X.left_op, map := λ (X Y : category_theory.cosimplicial_object.augmented Cᵒᵖ) (f : X ⟶ Y), quiver.hom.op {left := category_theory.nat_trans.left_op f.right, right := f.left.unop, w' := _}, map_id' := _, map_comp' := _}
The contravariant categorical equivalence between augmented simplicial objects and augmented cosimplicial objects in the opposite category.
Equations
- category_theory.simplicial_cosimplicial_augmented_equiv C = category_theory.equivalence.mk (category_theory.simplicial_to_cosimplicial_augmented C) (category_theory.cosimplicial_to_simplicial_augmented C) (category_theory.nat_iso.of_components (λ (X : (category_theory.simplicial_object.augmented C)ᵒᵖ), (opposite.unop X).right_op_left_op_iso.op) _) (category_theory.nat_iso.of_components (λ (X : category_theory.cosimplicial_object.augmented Cᵒᵖ), X.left_op_right_op_iso) _)