diff freyd2.agda @ 693:984518c56e96

fix
author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Mon, 13 Nov 2017 12:39:30 +0900
parents 917e51be9bbf
children 7a6ee564e3a8
line wrap: on
line diff
--- a/freyd2.agda	Sun Nov 12 10:01:06 2017 +0900
+++ b/freyd2.agda	Mon Nov 13 12:39:30 2017 +0900
@@ -12,19 +12,20 @@
 
 ----------
 --
+-- A is locally small complete and K{*}↓U has preinitial full subcategory, U is an adjoint functor
+--
 --    a : Obj A
 --    U : A → Sets
 --    U ⋍ Hom (a,-)
 --
 
--- maybe this is a part of local smallness
-postulate ≈-≡ :  { c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ )  {a b : Obj A } { x y : Hom A a b } →  (x≈y : A [ x ≈ y  ]) → x ≡ y
+-- A is localy small
+postulate ≡←≈ :  { c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ )  {a b : Obj A } { x y : Hom A a b } →  (x≈y : A [ x ≈ y  ]) → x ≡ y
 
 import Relation.Binary.PropositionalEquality
 -- Extensionality a b = {A : Set a} {B : A → Set b} {f g : (x : A) → B x} → (∀ x → f x ≡ g x) → f ≡ g → ( λ x → f x ≡ λ x → g x )
 postulate extensionality : { c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ ) → Relation.Binary.PropositionalEquality.Extensionality c₂ c₂
 
-
 ----
 --
 --  Hom ( a, - ) is Object mapping in Yoneda Functor
@@ -48,10 +49,10 @@
         } 
     }  where
         lemma-y-obj1 : {b : Obj A } → (x : Hom A a b) →  A [ id1 A b o x ] ≡ x
-        lemma-y-obj1 {b} x = let open ≈-Reasoning A  in ≈-≡ A idL
+        lemma-y-obj1 {b} x = let open ≈-Reasoning A  in ≡←≈ A idL
         lemma-y-obj2 :  (a₁ b c : Obj A) (f : Hom A a₁ b) (g : Hom A b c ) → (x : Hom A a a₁ )→ 
                A [ A [ g o f ] o x ] ≡ (Sets [ _[_o_] A g o _[_o_] A f ]) x
-        lemma-y-obj2 a₁ b c f g x = let open ≈-Reasoning A in ≈-≡ A ( begin
+        lemma-y-obj2 a₁ b c f g x = let open ≈-Reasoning A in ≡←≈ A ( begin
                A [ A [ g o f ] o x ]
              ≈↑⟨ assoc ⟩
                A [ g o A [ f o x ] ]
@@ -59,7 +60,7 @@
                ( λ x →  A [ g o x  ]  ) ( ( λ x → A [ f o x ] ) x )
              ∎ )
         lemma-y-obj3 :  {b c : Obj A} {f g : Hom A b c } → (x : Hom A a b ) → A [ f ≈ g ] →   A [ f o x ] ≡ A [ g o x ]
-        lemma-y-obj3 {_} {_} {f} {g} x eq =  let open ≈-Reasoning A in ≈-≡ A ( begin
+        lemma-y-obj3 {_} {_} {f} {g} x eq =  let open ≈-Reasoning A in ≡←≈ A ( begin
                 A [ f o x ]
              ≈⟨ resp refl-hom eq ⟩
                 A [ g o x ]
@@ -119,7 +120,7 @@
                  FMap Γ f o TMap t a₁ x
              ≈⟨⟩
                  ( ( FMap (Yoneda A b  ○ Γ ) f )  *  TMap t a₁ ) x
-             ≈⟨ ≡-≈ ( cong (λ k → k x ) (IsNTrans.commute (isNTrans t)) ) ⟩
+             ≈⟨ ≈←≡ ( cong (λ k → k x ) (IsNTrans.commute (isNTrans t)) ) ⟩
                  ( TMap t b₁ * ( FMap (K I Sets a) f ) ) x
              ≈⟨⟩
                  ( TMap t b₁ * id1 Sets a ) x
@@ -135,7 +136,7 @@
       ψ X t x = FMap (Yoneda A b) (limit (isLimit lim) b (ta X x t )) (id1 A b )
       t0f=t0 : (a : Obj Sets ) ( t : NTrans I Sets (K I Sets a) (Yoneda A b ○ Γ)) (i : Obj I)
            → Sets [ Sets [ TMap (LimitNat I A Sets Γ (a0 lim) (t0 lim) (Yoneda A b)) i o ψ a t ] ≈ TMap t i ]
-      t0f=t0 a t i = let open ≈-Reasoning A in extensionality A ( λ x →  ≈-≡ A ( begin 
+      t0f=t0 a t i = let open ≈-Reasoning A in extensionality A ( λ x →  ≡←≈ A ( begin 
                  ( Sets [ TMap (LimitNat I A Sets Γ (a0 lim) (t0 lim) (Yoneda A b)) i o ψ a t  ] ) x
              ≈⟨⟩
                 FMap (Yoneda A b) ( TMap (t0 lim) i) (FMap (Yoneda A b) (limit (isLimit lim) b (ta a x t )) (id1 A b ))
@@ -151,7 +152,7 @@
       limit-uniqueness0 :  {a : Obj Sets} {t : NTrans I Sets (K I Sets a) (Yoneda A b ○ Γ)} {f : Hom Sets a (FObj (Yoneda A b) (a0 lim))} →
         ({i : Obj I} → Sets [ Sets [ TMap (LimitNat I A Sets Γ (a0 lim) (t0 lim) (Yoneda A b)) i o f ] ≈ TMap t i ]) →
         Sets [ ψ a t ≈ f ]
-      limit-uniqueness0 {a} {t} {f} t0f=t = let open ≈-Reasoning A in extensionality A ( λ x →  ≈-≡ A ( begin 
+      limit-uniqueness0 {a} {t} {f} t0f=t = let open ≈-Reasoning A in extensionality A ( λ x →  ≡←≈ A ( begin 
                   ψ a t x
              ≈⟨⟩
                  FMap (Yoneda A b) (limit (isLimit lim) b (ta a x t )) (id1 A b )
@@ -159,7 +160,7 @@
                  limit (isLimit lim) b (ta a x t ) o id1 A b 
              ≈⟨ idR ⟩
                  limit (isLimit lim) b (ta a x t ) 
-             ≈⟨ limit-uniqueness (isLimit lim) ( λ {i} → ≡-≈ ( cong ( λ g → g x )( t0f=t {i} ))) ⟩
+             ≈⟨ limit-uniqueness (isLimit lim) ( λ {i} → ≈←≡ ( cong ( λ g → g x )( t0f=t {i} ))) ⟩
                   f x
              ∎  ))
 
@@ -191,7 +192,7 @@
          initObj  : Obj (K A Sets * ↓ Yoneda A a)
          initObj = record { obj = a ; hom = λ x → id1 A a }
          comm2 : (b : Obj commaCat) ( x : * ) → ( Sets [ FMap (Yoneda A a) (hom b OneObj) o (λ x₁ → id1 A a) ] )  x ≡ hom b x
-         comm2 b OneObj = let open ≈-Reasoning A in  ≈-≡ A ( begin
+         comm2 b OneObj = let open ≈-Reasoning A in  ≡←≈ A ( begin
                 ( Sets [ FMap (Yoneda A a) (hom b OneObj) o (λ x₁ → id1 A a) ] ) OneObj
              ≈⟨⟩
                 FMap (Yoneda A a) (hom b OneObj) (id1 A a)
@@ -228,7 +229,7 @@
                 ( Sets [ FMap  (Yoneda A a) (arrow f) o id1 Sets (FObj (Yoneda A a) a)  ] ) (id1 A a)
              ≈⟨⟩
                ( Sets [ FMap  (Yoneda A a) (arrow f) o ( λ x → id1 A a ) ] ) OneObj
-             ≈⟨ ≡-≈ ( cong (λ k → k OneObj ) (comm f )) ⟩
+             ≈⟨ ≈←≡ ( cong (λ k → k OneObj ) (comm f )) ⟩
                ( Sets [ hom b  o  FMap  (K A Sets *) (arrow f) ]  ) OneObj
              ≈⟨⟩
                 hom b OneObj
@@ -294,7 +295,7 @@
                  A [ f o arrow (initial In (ob A U a y)) ]
              ≡⟨⟩
                  A [ arrow ( fArrow A U f y ) o arrow (initial In (ob A U a y)) ]
-             ≡⟨  ≈-≡ A ( uniqueness In {ob A U b (FMap U f y) } (( K A Sets * ↓ U) [ fArrow A U f y  o initial In (ob A U a y)] ) ) ⟩
+             ≡⟨  ≡←≈ A ( uniqueness In {ob A U b (FMap U f y) } (( K A Sets * ↓ U) [ fArrow A U f y  o initial In (ob A U a y)] ) ) ⟩
                 arrow (initial In (ob A U b (FMap U f y) ))
              ≡⟨⟩
                 (Sets [ ( λ x → arrow (initial In (ob A U b x))) o FMap U f ] ) y
@@ -342,7 +343,7 @@
          → ( Sets [ FMap U y o hom i ] ) z ≡ ( Sets [ ub A U x (FMap U y (hom i OneObj)) o FMap (K A Sets *) y ] ) z 
       iso0 x y  OneObj = refl
       iso→  : {x : Obj A} → Sets [ Sets [ tmap1 x o tmap2 x ] ≈ id1 Sets (FObj (Yoneda A (obj i)) x) ]
-      iso→ {x} = let open ≈-Reasoning A in extensionality Sets ( λ ( y : Hom A (obj i ) x ) → ≈-≡ A ( begin
+      iso→ {x} = let open ≈-Reasoning A in extensionality Sets ( λ ( y : Hom A (obj i ) x ) → ≡←≈ A ( begin
                ( Sets [ tmap1 x o tmap2 x ] ) y
              ≈⟨⟩
                 arrow ( initial In (ob A U x (( FMap U y ) ( hom i OneObj ) ))) 
@@ -397,7 +398,7 @@
       B [ B [ FMap U g o  tmap-η a ]  ≈ f ] → A [ arrow (solution f)  ≈ g ]
    unique {a} {b} {f} {g} ugη=f = let open ≈-Reasoning A in begin
         arrow (solution f) 
-      ≈↑⟨ ≡-≈ ( cong (λ k → arrow (solution k)) ( ≈-≡ B ugη=f )) ⟩
+      ≈↑⟨ ≈←≡ ( cong (λ k → arrow (solution k)) ( ≡←≈ B ugη=f )) ⟩
         arrow (solution (B [ FMap U g o tmap-η a ] )) 
       ≈↑⟨ uniqueness (In a) (record { arrow = g ; comm = comm1 }) ⟩
         g