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Mathlib.CategoryTheory.Bicategory.Functor.Pseudofunctor

Pseudofunctors #

A pseudofunctor is an oplax (or lax) functor whose mapId and mapComp are isomorphisms. We provide several constructors for pseudofunctors:

Main definitions #

structure CategoryTheory.Pseudofunctor (B : Type u₁) [CategoryTheory.Bicategory B] (C : Type u₂) [CategoryTheory.Bicategory C] extends CategoryTheory.PrelaxFunctor B C :
Type (max (max (max (max (max u₁ u₂) v₁) v₂) w₁) w₂)

A pseudofunctor F between bicategories B and C consists of a function between objects F.obj, a function between 1-morphisms F.map, and a function between 2-morphisms F.map₂.

Unlike functors between categories, F.map do not need to strictly commute with the compositions, and do not need to strictly preserve the identity. Instead, there are specified 2-isomorphisms F.map (𝟙 a) ≅ 𝟙 (F.obj a) and F.map (f ≫ g) ≅ F.map f ≫ F.map g.

F.map₂ strictly commute with compositions and preserve the identity. They also preserve the associator, the left unitor, and the right unitor modulo some adjustments of domains and codomains of 2-morphisms.

Instances For
    theorem CategoryTheory.Pseudofunctor.map₂_whisker_left_assoc {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (self : CategoryTheory.Pseudofunctor B C) {a b c : B} (f : a b) {g h : b c} (η : g h) {Z : self.obj a self.obj c} (h✝ : self.map (CategoryTheory.CategoryStruct.comp f h) Z) :
    theorem CategoryTheory.Pseudofunctor.map₂_whisker_right_assoc {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (self : CategoryTheory.Pseudofunctor B C) {a b c : B} {f g : a b} (η : f g) (h : b c) {Z : self.obj a self.obj c} (h✝ : self.map (CategoryTheory.CategoryStruct.comp g h) Z) :
    theorem CategoryTheory.Pseudofunctor.map₂_whisker_left_app {B : Type u_1} [CategoryTheory.Bicategory B] (self : CategoryTheory.Pseudofunctor B CategoryTheory.Cat) {a b c : B} (f : a b) {g h : b c} (η : g h) (X : (self.obj a)) :
    (self.map₂ (CategoryTheory.Bicategory.whiskerLeft f η)).app X = CategoryTheory.CategoryStruct.comp ((self.mapComp f g).hom.app X) (CategoryTheory.CategoryStruct.comp ((self.map₂ η).app ((self.map f).obj X)) ((self.mapComp f h).inv.app X))
    theorem CategoryTheory.Pseudofunctor.map₂_whisker_right_app {B : Type u_1} [CategoryTheory.Bicategory B] (self : CategoryTheory.Pseudofunctor B CategoryTheory.Cat) {a b c : B} {f g : a b} (η : f g) (h : b c) (X : (self.obj a)) :
    (self.map₂ (CategoryTheory.Bicategory.whiskerRight η h)).app X = CategoryTheory.CategoryStruct.comp ((self.mapComp f h).hom.app X) (CategoryTheory.CategoryStruct.comp ((self.map h).map ((self.map₂ η).app X)) ((self.mapComp g h).inv.app X))
    theorem CategoryTheory.Pseudofunctor.map₂_associator_app {B : Type u_1} [CategoryTheory.Bicategory B] (self : CategoryTheory.Pseudofunctor B CategoryTheory.Cat) {a b c d : B} (f : a b) (g : b c) (h : c d) (X : (self.obj a)) :
    (self.map₂ (CategoryTheory.Bicategory.associator f g h).hom).app X = CategoryTheory.CategoryStruct.comp ((self.mapComp (CategoryTheory.CategoryStruct.comp f g) h).hom.app X) (CategoryTheory.CategoryStruct.comp ((self.map h).map ((self.mapComp f g).hom.app X)) (CategoryTheory.CategoryStruct.comp ((CategoryTheory.Bicategory.associator (self.map f) (self.map g) (self.map h)).hom.app X) (CategoryTheory.CategoryStruct.comp ((self.mapComp g h).inv.app ((self.map f).obj X)) ((self.mapComp f (CategoryTheory.CategoryStruct.comp g h)).inv.app X))))
    theorem CategoryTheory.Pseudofunctor.map₂_right_unitor_app {B : Type u_1} [CategoryTheory.Bicategory B] (self : CategoryTheory.Pseudofunctor B CategoryTheory.Cat) {a b : B} (f : a b) (X : (self.obj a)) :
    (self.map₂ (CategoryTheory.Bicategory.rightUnitor f).hom).app X = CategoryTheory.CategoryStruct.comp ((self.mapComp f (CategoryTheory.CategoryStruct.id b)).hom.app X) (CategoryTheory.CategoryStruct.comp ((self.mapId b).hom.app ((self.map f).obj X)) ((CategoryTheory.Bicategory.rightUnitor (self.map f)).hom.app X))
    theorem CategoryTheory.Pseudofunctor.map₂_left_unitor_app {B : Type u_1} [CategoryTheory.Bicategory B] (self : CategoryTheory.Pseudofunctor B CategoryTheory.Cat) {a b : B} (f : a b) (X : (self.obj a)) :
    (self.map₂ (CategoryTheory.Bicategory.leftUnitor f).hom).app X = CategoryTheory.CategoryStruct.comp ((self.mapComp (CategoryTheory.CategoryStruct.id a) f).hom.app X) (CategoryTheory.CategoryStruct.comp ((self.map f).map ((self.mapId a).hom.app X)) ((CategoryTheory.Bicategory.leftUnitor (self.map f)).hom.app X))

    The oplax functor associated with a pseudofunctor.

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    • One or more equations did not get rendered due to their size.
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      @[simp]
      theorem CategoryTheory.Pseudofunctor.toOplax_mapId {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.Pseudofunctor B C) (a : B) :
      F.toOplax.mapId a = (F.mapId a).hom
      @[simp]
      theorem CategoryTheory.Pseudofunctor.toOplax_toPrelaxFunctor {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.Pseudofunctor B C) :
      F.toOplax.toPrelaxFunctor = F.toPrelaxFunctor
      @[simp]
      theorem CategoryTheory.Pseudofunctor.toOplax_mapComp {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.Pseudofunctor B C) {a✝ b✝ c✝ : B} (f : a✝ b✝) (g : b✝ c✝) :
      F.toOplax.mapComp f g = (F.mapComp f g).hom
      Equations
      • CategoryTheory.Pseudofunctor.hasCoeToOplax = { coe := CategoryTheory.Pseudofunctor.toOplax }

      The Lax functor associated with a pseudofunctor.

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      • One or more equations did not get rendered due to their size.
      Instances For
        @[simp]
        theorem CategoryTheory.Pseudofunctor.toLax_toPrelaxFunctor {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.Pseudofunctor B C) :
        F.toLax.toPrelaxFunctor = F.toPrelaxFunctor
        @[simp]
        theorem CategoryTheory.Pseudofunctor.toLax_mapId {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.Pseudofunctor B C) (a : B) :
        F.toLax.mapId a = (F.mapId a).inv
        @[simp]
        theorem CategoryTheory.Pseudofunctor.toLax_mapComp {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.Pseudofunctor B C) {a✝ b✝ c✝ : B} (f : a✝ b✝) (g : b✝ c✝) :
        F.toLax.mapComp f g = (F.mapComp f g).inv
        Equations
        • CategoryTheory.Pseudofunctor.hasCoeToLax = { coe := CategoryTheory.Pseudofunctor.toLax }

        The identity pseudofunctor.

        Equations
        • One or more equations did not get rendered due to their size.
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          @[simp]
          Equations

          Composition of pseudofunctors.

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          • One or more equations did not get rendered due to their size.
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            @[simp]
            theorem CategoryTheory.Pseudofunctor.comp_toPrelaxFunctor {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] {D : Type u₃} [CategoryTheory.Bicategory D] (F : CategoryTheory.Pseudofunctor B C) (G : CategoryTheory.Pseudofunctor C D) :
            (F.comp G).toPrelaxFunctor = F.comp G.toPrelaxFunctor
            @[simp]
            theorem CategoryTheory.Pseudofunctor.comp_mapId {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] {D : Type u₃} [CategoryTheory.Bicategory D] (F : CategoryTheory.Pseudofunctor B C) (G : CategoryTheory.Pseudofunctor C D) (a : B) :
            (F.comp G).mapId a = G.map₂Iso (F.mapId a) ≪≫ G.mapId (F.obj a)
            @[simp]
            theorem CategoryTheory.Pseudofunctor.comp_mapComp {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] {D : Type u₃} [CategoryTheory.Bicategory D] (F : CategoryTheory.Pseudofunctor B C) (G : CategoryTheory.Pseudofunctor C D) {a✝ b✝ c✝ : B} (f : a✝ b✝) (g : b✝ c✝) :
            (F.comp G).mapComp f g = G.map₂Iso (F.mapComp f g) ≪≫ G.mapComp (F.map f) (F.map g)
            theorem CategoryTheory.Pseudofunctor.mapComp_assoc_right_hom_app {B : Type u_1} [CategoryTheory.Bicategory B] (F : CategoryTheory.Pseudofunctor B CategoryTheory.Cat) {a b c d : B} (f : a b) (g : b c) (h : c d) (X : (F.obj a)) :
            CategoryTheory.CategoryStruct.comp ((F.mapComp f (CategoryTheory.CategoryStruct.comp g h)).hom.app X) ((F.mapComp g h).hom.app ((F.map f).obj X)) = CategoryTheory.CategoryStruct.comp ((F.map₂ (CategoryTheory.Bicategory.associator f g h).inv).app X) (CategoryTheory.CategoryStruct.comp ((F.mapComp (CategoryTheory.CategoryStruct.comp f g) h).hom.app X) (CategoryTheory.CategoryStruct.comp ((F.map h).map ((F.mapComp f g).hom.app X)) ((CategoryTheory.Bicategory.associator (F.map f) (F.map g) (F.map h)).hom.app X)))
            theorem CategoryTheory.Pseudofunctor.mapComp_assoc_left_hom_app {B : Type u_1} [CategoryTheory.Bicategory B] (F : CategoryTheory.Pseudofunctor B CategoryTheory.Cat) {a b c d : B} (f : a b) (g : b c) (h : c d) (X : (F.obj a)) :
            CategoryTheory.CategoryStruct.comp ((F.mapComp (CategoryTheory.CategoryStruct.comp f g) h).hom.app X) ((F.map h).map ((F.mapComp f g).hom.app X)) = CategoryTheory.CategoryStruct.comp ((F.map₂ (CategoryTheory.Bicategory.associator f g h).hom).app X) (CategoryTheory.CategoryStruct.comp ((F.mapComp f (CategoryTheory.CategoryStruct.comp g h)).hom.app X) (CategoryTheory.CategoryStruct.comp ((F.mapComp g h).hom.app ((F.map f).obj X)) ((CategoryTheory.Bicategory.associator (F.map f) (F.map g) (F.map h)).inv.app X)))
            theorem CategoryTheory.Pseudofunctor.mapComp_assoc_right_inv_app {B : Type u_1} [CategoryTheory.Bicategory B] (F : CategoryTheory.Pseudofunctor B CategoryTheory.Cat) {a b c d : B} (f : a b) (g : b c) (h : c d) (X : (F.obj a)) :
            CategoryTheory.CategoryStruct.comp ((F.mapComp g h).inv.app ((F.map f).obj X)) ((F.mapComp f (CategoryTheory.CategoryStruct.comp g h)).inv.app X) = CategoryTheory.CategoryStruct.comp ((CategoryTheory.Bicategory.associator (F.map f) (F.map g) (F.map h)).inv.app X) (CategoryTheory.CategoryStruct.comp ((F.map h).map ((F.mapComp f g).inv.app X)) (CategoryTheory.CategoryStruct.comp ((F.mapComp (CategoryTheory.CategoryStruct.comp f g) h).inv.app X) ((F.map₂ (CategoryTheory.Bicategory.associator f g h).hom).app X)))
            theorem CategoryTheory.Pseudofunctor.mapComp_assoc_left_inv_app {B : Type u_1} [CategoryTheory.Bicategory B] (F : CategoryTheory.Pseudofunctor B CategoryTheory.Cat) {a b c d : B} (f : a b) (g : b c) (h : c d) (X : (F.obj a)) :
            CategoryTheory.CategoryStruct.comp ((F.map h).map ((F.mapComp f g).inv.app X)) ((F.mapComp (CategoryTheory.CategoryStruct.comp f g) h).inv.app X) = CategoryTheory.CategoryStruct.comp ((CategoryTheory.Bicategory.associator (F.map f) (F.map g) (F.map h)).hom.app X) (CategoryTheory.CategoryStruct.comp ((F.mapComp g h).inv.app ((F.map f).obj X)) (CategoryTheory.CategoryStruct.comp ((F.mapComp f (CategoryTheory.CategoryStruct.comp g h)).inv.app X) ((F.map₂ (CategoryTheory.Bicategory.associator f g h).inv).app X)))

            Construct a pseudofunctor from an oplax functor whose mapId and mapComp are isomorphisms.

            Equations
            • One or more equations did not get rendered due to their size.
            Instances For
              @[simp]
              @[simp]
              theorem CategoryTheory.Pseudofunctor.mkOfOplax_mapComp {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.OplaxFunctor B C) (F' : F.PseudoCore) {a✝ b✝ c✝ : B} (f : a✝ b✝) (g : b✝ c✝) :
              (CategoryTheory.Pseudofunctor.mkOfOplax F F').mapComp f g = F'.mapCompIso f g
              @[simp]
              theorem CategoryTheory.Pseudofunctor.mkOfOplax_mapId {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.OplaxFunctor B C) (F' : F.PseudoCore) (a : B) :
              (CategoryTheory.Pseudofunctor.mkOfOplax F F').mapId a = F'.mapIdIso a
              noncomputable def CategoryTheory.Pseudofunctor.mkOfOplax' {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.OplaxFunctor B C) [∀ (a : B), CategoryTheory.IsIso (F.mapId a)] [∀ {a b c : B} (f : a b) (g : b c), CategoryTheory.IsIso (F.mapComp f g)] :

              Construct a pseudofunctor from an oplax functor whose mapId and mapComp are isomorphisms.

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              • One or more equations did not get rendered due to their size.
              Instances For
                @[simp]
                theorem CategoryTheory.Pseudofunctor.mkOfOplax'_toPrelaxFunctor {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.OplaxFunctor B C) [∀ (a : B), CategoryTheory.IsIso (F.mapId a)] [∀ {a b c : B} (f : a b) (g : b c), CategoryTheory.IsIso (F.mapComp f g)] :
                (CategoryTheory.Pseudofunctor.mkOfOplax' F).toPrelaxFunctor = F.toPrelaxFunctor
                @[simp]
                theorem CategoryTheory.Pseudofunctor.mkOfOplax'_mapId_inv {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.OplaxFunctor B C) [∀ (a : B), CategoryTheory.IsIso (F.mapId a)] [∀ {a b c : B} (f : a b) (g : b c), CategoryTheory.IsIso (F.mapComp f g)] (a : B) :
                @[simp]
                theorem CategoryTheory.Pseudofunctor.mkOfOplax'_mapId_hom {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.OplaxFunctor B C) [∀ (a : B), CategoryTheory.IsIso (F.mapId a)] [∀ {a b c : B} (f : a b) (g : b c), CategoryTheory.IsIso (F.mapComp f g)] (a : B) :
                ((CategoryTheory.Pseudofunctor.mkOfOplax' F).mapId a).hom = F.mapId a
                @[simp]
                theorem CategoryTheory.Pseudofunctor.mkOfOplax'_mapComp_hom {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.OplaxFunctor B C) [∀ (a : B), CategoryTheory.IsIso (F.mapId a)] [∀ {a b c : B} (f : a b) (g : b c), CategoryTheory.IsIso (F.mapComp f g)] {a✝ b✝ c✝ : B} (f : a✝ b✝) (g : b✝ c✝) :
                ((CategoryTheory.Pseudofunctor.mkOfOplax' F).mapComp f g).hom = F.mapComp f g
                @[simp]
                theorem CategoryTheory.Pseudofunctor.mkOfOplax'_mapComp_inv {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.OplaxFunctor B C) [∀ (a : B), CategoryTheory.IsIso (F.mapId a)] [∀ {a b c : B} (f : a b) (g : b c), CategoryTheory.IsIso (F.mapComp f g)] {a✝ b✝ c✝ : B} (f : a✝ b✝) (g : b✝ c✝) :
                ((CategoryTheory.Pseudofunctor.mkOfOplax' F).mapComp f g).inv = CategoryTheory.inv (F.mapComp f g)

                Construct a pseudofunctor from a lax functor whose mapId and mapComp are isomorphisms.

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                • One or more equations did not get rendered due to their size.
                Instances For
                  @[simp]
                  theorem CategoryTheory.Pseudofunctor.mkOfLax_toPrelaxFunctor {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.LaxFunctor B C) (F' : F.PseudoCore) :
                  (CategoryTheory.Pseudofunctor.mkOfLax F F').toPrelaxFunctor = F.toPrelaxFunctor
                  @[simp]
                  theorem CategoryTheory.Pseudofunctor.mkOfLax_mapComp {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.LaxFunctor B C) (F' : F.PseudoCore) {a✝ b✝ c✝ : B} (f : a✝ b✝) (g : b✝ c✝) :
                  (CategoryTheory.Pseudofunctor.mkOfLax F F').mapComp f g = F'.mapCompIso f g
                  @[simp]
                  theorem CategoryTheory.Pseudofunctor.mkOfLax_mapId {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.LaxFunctor B C) (F' : F.PseudoCore) (a : B) :
                  (CategoryTheory.Pseudofunctor.mkOfLax F F').mapId a = F'.mapIdIso a
                  noncomputable def CategoryTheory.Pseudofunctor.mkOfLax' {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.LaxFunctor B C) [∀ (a : B), CategoryTheory.IsIso (F.mapId a)] [∀ {a b c : B} (f : a b) (g : b c), CategoryTheory.IsIso (F.mapComp f g)] :

                  Construct a pseudofunctor from a lax functor whose mapId and mapComp are isomorphisms.

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                  • One or more equations did not get rendered due to their size.
                  Instances For
                    @[simp]
                    theorem CategoryTheory.Pseudofunctor.mkOfLax'_mapComp_hom {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.LaxFunctor B C) [∀ (a : B), CategoryTheory.IsIso (F.mapId a)] [∀ {a b c : B} (f : a b) (g : b c), CategoryTheory.IsIso (F.mapComp f g)] {a✝ b✝ c✝ : B} (f : a✝ b✝) (g : b✝ c✝) :
                    ((CategoryTheory.Pseudofunctor.mkOfLax' F).mapComp f g).hom = CategoryTheory.inv (F.mapComp f g)
                    @[simp]
                    theorem CategoryTheory.Pseudofunctor.mkOfLax'_mapId_inv {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.LaxFunctor B C) [∀ (a : B), CategoryTheory.IsIso (F.mapId a)] [∀ {a b c : B} (f : a b) (g : b c), CategoryTheory.IsIso (F.mapComp f g)] (a : B) :
                    ((CategoryTheory.Pseudofunctor.mkOfLax' F).mapId a).inv = F.mapId a
                    @[simp]
                    theorem CategoryTheory.Pseudofunctor.mkOfLax'_mapId_hom {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.LaxFunctor B C) [∀ (a : B), CategoryTheory.IsIso (F.mapId a)] [∀ {a b c : B} (f : a b) (g : b c), CategoryTheory.IsIso (F.mapComp f g)] (a : B) :
                    @[simp]
                    theorem CategoryTheory.Pseudofunctor.mkOfLax'_toPrelaxFunctor {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.LaxFunctor B C) [∀ (a : B), CategoryTheory.IsIso (F.mapId a)] [∀ {a b c : B} (f : a b) (g : b c), CategoryTheory.IsIso (F.mapComp f g)] :
                    (CategoryTheory.Pseudofunctor.mkOfLax' F).toPrelaxFunctor = F.toPrelaxFunctor
                    @[simp]
                    theorem CategoryTheory.Pseudofunctor.mkOfLax'_mapComp_inv {B : Type u₁} [CategoryTheory.Bicategory B] {C : Type u₂} [CategoryTheory.Bicategory C] (F : CategoryTheory.LaxFunctor B C) [∀ (a : B), CategoryTheory.IsIso (F.mapId a)] [∀ {a b c : B} (f : a b) (g : b c), CategoryTheory.IsIso (F.mapComp f g)] {a✝ b✝ c✝ : B} (f : a✝ b✝) (g : b✝ c✝) :
                    ((CategoryTheory.Pseudofunctor.mkOfLax' F).mapComp f g).inv = F.mapComp f g