Mercurial > hg > Members > kono > Proof > category
annotate cat-utility.agda @ 639:4cf8f982dc5b
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| author | Shinji KONO <kono@ie.u-ryukyu.ac.jp> |
|---|---|
| date | Sun, 02 Jul 2017 02:18:57 +0900 |
| parents | b035cd3be525 |
| children | e1d54c0f73a7 |
| rev | line source |
|---|---|
| 56 | 1 module cat-utility where |
| 2 | |
| 3 -- Shinji KONO <kono@ie.u-ryukyu.ac.jp> | |
| 4 | |
| 87 | 5 open import Category -- https://github.com/konn/category-agda |
| 6 open import Level | |
| 7 --open import Category.HomReasoning | |
| 8 open import HomReasoning | |
| 56 | 9 |
| 87 | 10 open Functor |
| 56 | 11 |
| 87 | 12 id1 : ∀{c₁ c₂ ℓ : Level} (A : Category c₁ c₂ ℓ) (a : Obj A ) → Hom A a a |
| 13 id1 A a = (Id {_} {_} {_} {A} a) | |
| 253 | 14 -- We cannot make A implicit |
| 56 | 15 |
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16 record IsUniversalMapping {c₁ c₂ ℓ c₁' c₂' ℓ' : Level} (A : Category c₁ c₂ ℓ) (B : Category c₁' c₂' ℓ') |
| 87 | 17 ( U : Functor B A ) |
| 18 ( F : Obj A → Obj B ) | |
| 19 ( η : (a : Obj A) → Hom A a ( FObj U (F a) ) ) | |
| 20 ( _* : { a : Obj A}{ b : Obj B} → ( Hom A a (FObj U b) ) → Hom B (F a ) b ) | |
| 21 : Set (suc (c₁ ⊔ c₂ ⊔ ℓ ⊔ c₁' ⊔ c₂' ⊔ ℓ' )) where | |
| 22 field | |
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23 universalMapping : {a : Obj A} { b : Obj B } → { f : Hom A a (FObj U b) } → |
| 101 | 24 A [ A [ FMap U ( f * ) o η a ] ≈ f ] |
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25 uniquness : {a : Obj A} { b : Obj B } → { f : Hom A a (FObj U b) } → { g : Hom B (F a) b } → |
| 101 | 26 A [ A [ FMap U g o η a ] ≈ f ] → B [ f * ≈ g ] |
| 56 | 27 |
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28 record UniversalMapping {c₁ c₂ ℓ c₁' c₂' ℓ' : Level} (A : Category c₁ c₂ ℓ) (B : Category c₁' c₂' ℓ') |
| 87 | 29 ( U : Functor B A ) |
| 30 ( F : Obj A → Obj B ) | |
| 31 ( η : (a : Obj A) → Hom A a ( FObj U (F a) ) ) | |
| 32 : Set (suc (c₁ ⊔ c₂ ⊔ ℓ ⊔ c₁' ⊔ c₂' ⊔ ℓ' )) where | |
| 33 infixr 11 _* | |
| 34 field | |
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35 _* : { a : Obj A}{ b : Obj B} → ( Hom A a (FObj U b) ) → Hom B (F a ) b |
| 87 | 36 isUniversalMapping : IsUniversalMapping A B U F η _* |
| 56 | 37 |
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38 record coIsUniversalMapping {c₁ c₂ ℓ c₁' c₂' ℓ' : Level} (A : Category c₁ c₂ ℓ) (B : Category c₁' c₂' ℓ') |
| 268 | 39 ( F : Functor A B ) |
| 40 ( U : Obj B → Obj A ) | |
| 41 ( ε : (b : Obj B) → Hom B ( FObj F (U b) ) b ) | |
| 42 ( _*' : { b : Obj B}{ a : Obj A} → ( Hom B (FObj F a) b ) → Hom A a (U b ) ) | |
| 43 : Set (suc (c₁ ⊔ c₂ ⊔ ℓ ⊔ c₁' ⊔ c₂' ⊔ ℓ' )) where | |
| 44 field | |
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45 couniversalMapping : {b : Obj B} { a : Obj A } → { f : Hom B (FObj F a) b } → |
| 268 | 46 B [ B [ ε b o FMap F ( f *' ) ] ≈ f ] |
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47 couniquness : {b : Obj B} { a : Obj A } → { f : Hom B (FObj F a) b } → { g : Hom A a (U b) } → |
| 268 | 48 B [ B [ ε b o FMap F g ] ≈ f ] → A [ f *' ≈ g ] |
| 49 | |
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50 record coUniversalMapping {c₁ c₂ ℓ c₁' c₂' ℓ' : Level} (A : Category c₁ c₂ ℓ) (B : Category c₁' c₂' ℓ') |
| 268 | 51 ( F : Functor A B ) |
| 52 ( U : Obj B → Obj A ) | |
| 53 ( ε : (b : Obj B) → Hom B ( FObj F (U b) ) b ) | |
| 54 : Set (suc (c₁ ⊔ c₂ ⊔ ℓ ⊔ c₁' ⊔ c₂' ⊔ ℓ' )) where | |
| 55 infixr 11 _*' | |
| 56 field | |
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57 _*' : { b : Obj B}{ a : Obj A} → ( Hom B (FObj F a) b ) → Hom A a (U b ) |
| 268 | 58 iscoUniversalMapping : coIsUniversalMapping A B F U ε _*' |
| 59 | |
| 87 | 60 open NTrans |
| 61 open import Category.Cat | |
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62 record IsAdjunction {c₁ c₂ ℓ c₁' c₂' ℓ' : Level} (A : Category c₁ c₂ ℓ) (B : Category c₁' c₂' ℓ') |
| 87 | 63 ( U : Functor B A ) |
| 64 ( F : Functor A B ) | |
| 65 ( η : NTrans A A identityFunctor ( U ○ F ) ) | |
| 66 ( ε : NTrans B B ( F ○ U ) identityFunctor ) | |
| 67 : Set (suc (c₁ ⊔ c₂ ⊔ ℓ ⊔ c₁' ⊔ c₂' ⊔ ℓ' )) where | |
| 68 field | |
| 69 adjoint1 : { b : Obj B } → | |
| 70 A [ A [ ( FMap U ( TMap ε b )) o ( TMap η ( FObj U b )) ] ≈ id1 A (FObj U b) ] | |
| 71 adjoint2 : {a : Obj A} → | |
| 72 B [ B [ ( TMap ε ( FObj F a )) o ( FMap F ( TMap η a )) ] ≈ id1 B (FObj F a) ] | |
| 56 | 73 |
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74 record Adjunction {c₁ c₂ ℓ c₁' c₂' ℓ' : Level} (A : Category c₁ c₂ ℓ) (B : Category c₁' c₂' ℓ') |
| 87 | 75 ( U : Functor B A ) |
| 76 ( F : Functor A B ) | |
| 77 ( η : NTrans A A identityFunctor ( U ○ F ) ) | |
| 78 ( ε : NTrans B B ( F ○ U ) identityFunctor ) | |
| 79 : Set (suc (c₁ ⊔ c₂ ⊔ ℓ ⊔ c₁' ⊔ c₂' ⊔ ℓ' )) where | |
| 80 field | |
| 81 isAdjunction : IsAdjunction A B U F η ε | |
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82 U-functor = U |
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83 F-functor = F |
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84 Eta = η |
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85 Epsiron = ε |
| 56 | 86 |
| 87 | |
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88 record IsMonad {c₁ c₂ ℓ : Level} (A : Category c₁ c₂ ℓ) |
| 87 | 89 ( T : Functor A A ) |
| 90 ( η : NTrans A A identityFunctor T ) | |
| 91 ( μ : NTrans A A (T ○ T) T) | |
| 92 : Set (suc (c₁ ⊔ c₂ ⊔ ℓ )) where | |
| 93 field | |
| 94 assoc : {a : Obj A} → A [ A [ TMap μ a o TMap μ ( FObj T a ) ] ≈ A [ TMap μ a o FMap T (TMap μ a) ] ] | |
| 95 unity1 : {a : Obj A} → A [ A [ TMap μ a o TMap η ( FObj T a ) ] ≈ Id {_} {_} {_} {A} (FObj T a) ] | |
| 96 unity2 : {a : Obj A} → A [ A [ TMap μ a o (FMap T (TMap η a ))] ≈ Id {_} {_} {_} {A} (FObj T a) ] | |
| 56 | 97 |
| 87 | 98 record Monad {c₁ c₂ ℓ : Level} (A : Category c₁ c₂ ℓ) (T : Functor A A) (η : NTrans A A identityFunctor T) (μ : NTrans A A (T ○ T) T) |
| 99 : Set (suc (c₁ ⊔ c₂ ⊔ ℓ )) where | |
| 100 field | |
| 101 isMonad : IsMonad A T η μ | |
| 130 | 102 -- g ○ f = μ(c) T(g) f |
| 103 join : { a b : Obj A } → { c : Obj A } → | |
| 104 ( Hom A b ( FObj T c )) → ( Hom A a ( FObj T b)) → Hom A a ( FObj T c ) | |
| 105 join {_} {_} {c} g f = A [ TMap μ c o A [ FMap T g o f ] ] | |
| 106 | |
| 56 | 107 |
| 87 | 108 Functor*Nat : {c₁ c₂ ℓ c₁' c₂' ℓ' c₁'' c₂'' ℓ'' : Level} (A : Category c₁ c₂ ℓ) {B : Category c₁' c₂' ℓ'} (C : Category c₁'' c₂'' ℓ'') |
| 300 | 109 (F : Functor B C) → { G H : Functor A B } → ( n : NTrans A B G H ) → NTrans A C (F ○ G) (F ○ H) |
| 87 | 110 Functor*Nat A {B} C F {G} {H} n = record { |
| 300 | 111 TMap = λ a → FMap F (TMap n a) |
| 87 | 112 ; isNTrans = record { |
| 130 | 113 commute = commute |
| 87 | 114 } |
| 115 } where | |
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116 commute : {a b : Obj A} {f : Hom A a b} |
| 87 | 117 → C [ C [ (FMap F ( FMap H f )) o ( FMap F (TMap n a)) ] ≈ C [ (FMap F (TMap n b )) o (FMap F (FMap G f)) ] ] |
| 130 | 118 commute {a} {b} {f} = let open ≈-Reasoning (C) in |
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119 begin |
| 87 | 120 (FMap F ( FMap H f )) o ( FMap F (TMap n a)) |
| 121 ≈⟨ sym (distr F) ⟩ | |
| 122 FMap F ( B [ (FMap H f) o TMap n a ]) | |
| 123 ≈⟨ IsFunctor.≈-cong (isFunctor F) ( nat n ) ⟩ | |
| 124 FMap F ( B [ (TMap n b ) o FMap G f ] ) | |
| 125 ≈⟨ distr F ⟩ | |
| 126 (FMap F (TMap n b )) o (FMap F (FMap G f)) | |
| 127 ∎ | |
| 56 | 128 |
| 87 | 129 Nat*Functor : {c₁ c₂ ℓ c₁' c₂' ℓ' c₁'' c₂'' ℓ'' : Level} (A : Category c₁ c₂ ℓ) {B : Category c₁' c₂' ℓ'} (C : Category c₁'' c₂'' ℓ'') |
| 300 | 130 { G H : Functor B C } → ( n : NTrans B C G H ) → (F : Functor A B) → NTrans A C (G ○ F) (H ○ F) |
| 87 | 131 Nat*Functor A {B} C {G} {H} n F = record { |
| 300 | 132 TMap = λ a → TMap n (FObj F a) |
| 87 | 133 ; isNTrans = record { |
| 130 | 134 commute = commute |
| 87 | 135 } |
| 136 } where | |
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137 commute : {a b : Obj A} {f : Hom A a b} |
| 87 | 138 → C [ C [ ( FMap H (FMap F f )) o ( TMap n (FObj F a)) ] ≈ C [ (TMap n (FObj F b )) o (FMap G (FMap F f)) ] ] |
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139 commute {a} {b} {f} = IsNTrans.commute ( isNTrans n) |
| 56 | 140 |
| 87 | 141 -- T ≃ (U_R ○ F_R) |
| 142 -- μ = U_R ε F_R | |
| 143 -- nat-ε | |
| 144 -- nat-η -- same as η but has different types | |
| 84 | 145 |
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146 record MResolution {c₁ c₂ ℓ c₁' c₂' ℓ' : Level} (A : Category c₁ c₂ ℓ) ( B : Category c₁' c₂' ℓ' ) |
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147 ( T : Functor A A ) |
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148 -- { η : NTrans A A identityFunctor T } |
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149 -- { μ : NTrans A A (T ○ T) T } |
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150 -- { M : Monad A T η μ } |
| 87 | 151 ( UR : Functor B A ) ( FR : Functor A B ) |
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152 { ηR : NTrans A A identityFunctor ( UR ○ FR ) } |
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153 { εR : NTrans B B ( FR ○ UR ) identityFunctor } |
| 87 | 154 { μR : NTrans A A ( (UR ○ FR) ○ ( UR ○ FR )) ( UR ○ FR ) } |
| 155 ( Adj : Adjunction A B UR FR ηR εR ) | |
| 156 : Set (suc (c₁ ⊔ c₂ ⊔ ℓ ⊔ c₁' ⊔ c₂' ⊔ ℓ' )) where | |
| 157 field | |
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158 T=UF : T ≃ (UR ○ FR) |
| 300 | 159 μ=UεF : {x : Obj A } → A [ TMap μR x ≈ FMap UR ( TMap εR ( FObj FR x ) ) ] |
| 160 -- ηR=η : {x : Obj A } → A [ TMap ηR x ≈ TMap η x ] -- We need T → UR FR conversion | |
| 161 -- μR=μ : {x : Obj A } → A [ TMap μR x ≈ TMap μ x ] | |
| 86 | 162 |
| 88 | 163 |
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164 -- |
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165 -- e f |
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166 -- c -------→ a ---------→ b |
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167 -- ^ . ---------→ |
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168 -- | . g |
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169 -- |k . |
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170 -- | . h |
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171 -- d |
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172 |
| 443 | 173 record IsEqualizer { c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ ) {c a b : Obj A} (e : Hom A c a) (f g : Hom A a b) : Set (ℓ ⊔ (c₁ ⊔ c₂)) where |
| 260 | 174 field |
| 175 fe=ge : A [ A [ f o e ] ≈ A [ g o e ] ] | |
| 176 k : {d : Obj A} (h : Hom A d a) → A [ A [ f o h ] ≈ A [ g o h ] ] → Hom A d c | |
| 177 ek=h : {d : Obj A} → ∀ {h : Hom A d a} → {eq : A [ A [ f o h ] ≈ A [ g o h ] ] } → A [ A [ e o k {d} h eq ] ≈ h ] | |
| 178 uniqueness : {d : Obj A} → ∀ {h : Hom A d a} → {eq : A [ A [ f o h ] ≈ A [ g o h ] ] } → {k' : Hom A d c } → | |
| 179 A [ A [ e o k' ] ≈ h ] → A [ k {d} h eq ≈ k' ] | |
| 443 | 180 equalizer1 : Hom A c a |
| 181 equalizer1 = e | |
| 260 | 182 |
| 443 | 183 record Equalizer { c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ ) {a b : Obj A} (f g : Hom A a b) : Set (ℓ ⊔ (c₁ ⊔ c₂)) where |
| 440 | 184 field |
| 443 | 185 equalizer-c : Obj A |
| 186 equalizer : Hom A equalizer-c a | |
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187 isEqualizer : IsEqualizer A equalizer f g |
| 440 | 188 |
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189 -- |
| 260 | 190 -- Product |
| 191 -- | |
| 264 | 192 -- c |
| 193 -- f | g | |
| 194 -- |f×g | |
| 195 -- v | |
| 300 | 196 -- a <-------- ab ---------→ b |
| 264 | 197 -- π1 π2 |
| 260 | 198 |
| 199 | |
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200 record Product { c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ ) (a b ab : Obj A) |
| 260 | 201 ( π1 : Hom A ab a ) |
| 202 ( π2 : Hom A ab b ) | |
| 203 : Set (ℓ ⊔ (c₁ ⊔ c₂)) where | |
| 204 field | |
| 205 _×_ : {c : Obj A} ( f : Hom A c a ) → ( g : Hom A c b ) → Hom A c ab | |
| 206 π1fxg=f : {c : Obj A} { f : Hom A c a } → { g : Hom A c b } → A [ A [ π1 o ( f × g ) ] ≈ f ] | |
| 207 π2fxg=g : {c : Obj A} { f : Hom A c a } → { g : Hom A c b } → A [ A [ π2 o ( f × g ) ] ≈ g ] | |
| 208 uniqueness : {c : Obj A} { h : Hom A c ab } → A [ ( A [ π1 o h ] ) × ( A [ π2 o h ] ) ≈ h ] | |
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209 ×-cong : {c : Obj A} { f f' : Hom A c a } → { g g' : Hom A c b } → A [ f ≈ f' ] → A [ g ≈ g' ] → A [ f × g ≈ f' × g' ] |
| 440 | 210 |
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211 record CreateProduct { c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ ) |
| 440 | 212 : Set (ℓ ⊔ (c₁ ⊔ c₂)) where |
| 213 field | |
| 214 product : (a b : Obj A) -> Obj A | |
|
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215 π1 : (a b : Obj A) -> Hom A (product a b ) a |
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216 π2 : (a b : Obj A) -> Hom A (product a b ) b |
| 440 | 217 isProduct : (a b : Obj A) -> Product A a b (product a b) (π1 a b ) (π2 a b) |
| 260 | 218 |
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219 ----- |
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220 -- |
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221 -- product on arbitrary index |
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222 -- |
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223 |
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224 record IsIProduct { c c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ ) ( I : Set c) |
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225 ( p : Obj A ) -- product |
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226 ( ai : I → Obj A ) -- families |
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227 ( pi : (i : I ) → Hom A p ( ai i ) ) -- projections |
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228 : Set (c ⊔ ℓ ⊔ (c₁ ⊔ c₂)) where |
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229 field |
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230 iproduct : {q : Obj A} → ( qi : (i : I) → Hom A q (ai i) ) → Hom A q p |
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231 pif=q : {q : Obj A} → ( qi : (i : I) → Hom A q (ai i) ) → ∀ { i : I } → A [ A [ ( pi i ) o ( iproduct qi ) ] ≈ (qi i) ] |
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232 ip-uniqueness : {q : Obj A} { h : Hom A q p } → A [ iproduct ( λ (i : I) → A [ (pi i) o h ] ) ≈ h ] |
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233 ip-cong : {q : Obj A} → { qi : (i : I) → Hom A q (ai i) } → { qi' : (i : I) → Hom A q (ai i) } |
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234 → ( ∀ (i : I ) → A [ qi i ≈ qi' i ] ) → A [ iproduct qi ≈ iproduct qi' ] |
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235 -- another form of uniquness |
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236 ip-uniqueness1 : {q : Obj A} → ( qi : (i : I) → Hom A q (ai i) ) → ( product' : Hom A q p ) |
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237 → ( ∀ { i : I } → A [ A [ ( pi i ) o product' ] ≈ (qi i) ] ) |
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238 → A [ product' ≈ iproduct qi ] |
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239 ip-uniqueness1 {a} qi product' eq = let open ≈-Reasoning (A) in begin |
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240 product' |
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241 ≈↑⟨ ip-uniqueness ⟩ |
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242 iproduct (λ i₁ → A [ pi i₁ o product' ]) |
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243 ≈⟨ ip-cong ( λ i → begin |
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244 pi i o product' |
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245 ≈⟨ eq {i} ⟩ |
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246 qi i |
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247 ∎ ) ⟩ |
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248 iproduct qi |
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249 ∎ |
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250 |
|
508
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251 record IProduct { c c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ ) ( I : Set c) : Set (c ⊔ ℓ ⊔ (c₁ ⊔ c₂)) where |
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252 field |
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253 ai : I → Obj A |
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254 iprod : Obj A |
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255 pi : (i : I ) → Hom A iprod ( ai i ) |
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256 isIProduct : IsIProduct A I iprod ai pi |
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257 |
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258 |
| 260 | 259 -- Pullback |
| 260 -- f | |
| 300 | 261 -- a ------→ c |
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262 -- ^ ^ |
| 260 | 263 -- π1 | |g |
| 264 -- | | | |
| 300 | 265 -- ab ------→ b |
| 260 | 266 -- ^ π2 |
| 267 -- | | |
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268 -- d |
| 260 | 269 -- |
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270 record Pullback { c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ ) (a b c ab : Obj A) |
| 260 | 271 ( f : Hom A a c ) ( g : Hom A b c ) |
| 272 ( π1 : Hom A ab a ) ( π2 : Hom A ab b ) | |
| 273 : Set (ℓ ⊔ (c₁ ⊔ c₂)) where | |
| 274 field | |
| 275 commute : A [ A [ f o π1 ] ≈ A [ g o π2 ] ] | |
| 276 p : { d : Obj A } → { π1' : Hom A d a } { π2' : Hom A d b } → A [ A [ f o π1' ] ≈ A [ g o π2' ] ] → Hom A d ab | |
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277 π1p=π1 : { d : Obj A } → { π1' : Hom A d a } { π2' : Hom A d b } → { eq : A [ A [ f o π1' ] ≈ A [ g o π2' ] ] } |
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278 → A [ A [ π1 o p eq ] ≈ π1' ] |
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279 π2p=π2 : { d : Obj A } → { π1' : Hom A d a } { π2' : Hom A d b } → { eq : A [ A [ f o π1' ] ≈ A [ g o π2' ] ] } |
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280 → A [ A [ π2 o p eq ] ≈ π2' ] |
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281 uniqueness : { d : Obj A } → ( p' : Hom A d ab ) → { π1' : Hom A d a } { π2' : Hom A d b } → { eq : A [ A [ f o π1' ] ≈ A [ g o π2' ] ] } |
| 260 | 282 → { π1p=π1' : A [ A [ π1 o p' ] ≈ π1' ] } |
| 283 → { π2p=π2' : A [ A [ π2 o p' ] ≈ π2' ] } | |
| 284 → A [ p eq ≈ p' ] | |
| 285 axb : Obj A | |
| 286 axb = ab | |
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287 pi1 : Hom A ab a |
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288 pi1 = π1 |
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289 pi2 : Hom A ab b |
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290 pi2 = π2 |
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312
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291 |
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292 -- |
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293 -- Limit |
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294 -- |
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295 ----- |
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296 |
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297 -- Constancy Functor |
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298 |
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299 K : { c₁' c₂' ℓ' : Level} (A : Category c₁' c₂' ℓ') { c₁'' c₂'' ℓ'' : Level} ( I : Category c₁'' c₂'' ℓ'' ) |
|
312
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300 → ( a : Obj A ) → Functor I A |
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301 K A I a = record { |
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302 FObj = λ i → a ; |
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303 FMap = λ f → id1 A a ; |
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304 isFunctor = let open ≈-Reasoning (A) in record { |
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305 ≈-cong = λ f=g → refl-hom |
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306 ; identity = refl-hom |
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307 ; distr = sym idL |
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308 } |
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309 } |
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310 |
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311 |
| 487 | 312 record IsLimit { c₁' c₂' ℓ' : Level} { c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ ) ( I : Category c₁' c₂' ℓ' ) ( Γ : Functor I A ) |
| 313 (a0 : Obj A ) (t0 : NTrans I A ( K A I a0 ) Γ ) : Set (suc (c₁' ⊔ c₂' ⊔ ℓ' ⊔ c₁ ⊔ c₂ ⊔ ℓ )) where | |
|
312
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314 field |
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315 limit : ( a : Obj A ) → ( t : NTrans I A ( K A I a ) Γ ) → Hom A a a0 |
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316 t0f=t : { a : Obj A } → { t : NTrans I A ( K A I a ) Γ } → ∀ { i : Obj I } → |
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317 A [ A [ TMap t0 i o limit a t ] ≈ TMap t i ] |
| 495 | 318 limit-uniqueness : { a : Obj A } → { t : NTrans I A ( K A I a ) Γ } → { f : Hom A a a0 } → ( ∀ { i : Obj I } → |
|
312
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319 A [ A [ TMap t0 i o f ] ≈ TMap t i ] ) → A [ limit a t ≈ f ] |
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320 |
| 487 | 321 record Limit { c₁' c₂' ℓ' : Level} { c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ ) ( I : Category c₁' c₂' ℓ' ) ( Γ : Functor I A ) |
| 322 : Set (suc (c₁' ⊔ c₂' ⊔ ℓ' ⊔ c₁ ⊔ c₂ ⊔ ℓ )) where | |
| 323 field | |
| 324 a0 : Obj A | |
| 325 t0 : NTrans I A ( K A I a0 ) Γ | |
| 326 isLimit : IsLimit A I Γ a0 t0 | |
| 327 | |
| 328 LimitNat : { c₁' c₂' ℓ' : Level} (B : Category c₁' c₂' ℓ') { c₁ c₂ ℓ : Level} ( I : Category c₁ c₂ ℓ ) { c₁'' c₂'' ℓ'' : Level} | |
| 329 ( C : Category c₁'' c₂'' ℓ'' ) | |
| 330 ( Γ : Functor I B ) | |
| 331 ( lim : Obj B ) ( tb : NTrans I B ( K B I lim ) Γ ) → | |
| 332 ( U : Functor B C) → NTrans I C ( K C I (FObj U lim) ) (U ○ Γ) | |
| 333 LimitNat B I C Γ lim tb U = record { | |
| 334 TMap = TMap (Functor*Nat I C U tb) ; | |
| 335 isNTrans = record { commute = λ {a} {b} {f} → let open ≈-Reasoning (C) in begin | |
| 336 FMap (U ○ Γ) f o TMap (Functor*Nat I C U tb) a | |
| 337 ≈⟨ nat ( Functor*Nat I C U tb ) ⟩ | |
| 338 TMap (Functor*Nat I C U tb) b o FMap (U ○ K B I lim) f | |
| 339 ≈⟨ cdr (IsFunctor.identity (isFunctor U) ) ⟩ | |
| 340 TMap (Functor*Nat I C U tb) b o FMap (K C I (FObj U lim)) f | |
| 341 ∎ | |
| 342 } } | |
| 343 | |
| 344 open Limit | |
| 345 record LimitPreserve { c₁' c₂' ℓ' : Level} { c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ ) ( I : Category c₁' c₂' ℓ' ) | |
| 346 { c₁'' c₂'' ℓ'' : Level} ( C : Category c₁'' c₂'' ℓ'' ) | |
| 347 (G : Functor A C) : Set (suc (c₁' ⊔ c₂' ⊔ ℓ' ⊔ c₁ ⊔ c₂ ⊔ ℓ ⊔ c₁'' ⊔ c₂'' ⊔ ℓ'' )) where | |
| 348 field | |
| 349 preserve : ( Γ : Functor I A ) → ( limita : Limit A I Γ ) → | |
| 350 IsLimit C I (G ○ Γ) (FObj G (a0 limita ) ) (LimitNat A I C Γ (a0 limita ) (t0 limita) G ) | |
| 492 | 351 plimit : { Γ : Functor I A } → ( limita : Limit A I Γ ) → Limit C I (G ○ Γ ) |
| 352 plimit {Γ} limita = record { a0 = (FObj G (a0 limita )) | |
| 487 | 353 ; t0 = LimitNat A I C Γ (a0 limita ) (t0 limita) G |
| 354 ; isLimit = preserve Γ limita } | |
| 355 | |
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356 record CreateLimit { c₁' c₂' ℓ' : Level} { c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ ) ( I : Category c₁' c₂' ℓ' ) |
| 440 | 357 : Set (suc (c₁' ⊔ c₂' ⊔ ℓ' ⊔ c₁ ⊔ c₂ ⊔ ℓ )) where |
| 358 field | |
| 487 | 359 climit : ( Γ : Functor I A ) -> Limit A I Γ |
| 440 | 360 |
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361 record Complete { c₁' c₂' ℓ' : Level} { c₁ c₂ ℓ : Level} ( A : Category c₁ c₂ ℓ ) ( I : Category c₁' c₂' ℓ' ) |
| 440 | 362 : Set (suc (c₁' ⊔ c₂' ⊔ ℓ' ⊔ c₁ ⊔ c₂ ⊔ ℓ )) where |
| 363 field | |
| 487 | 364 climit : ( Γ : Functor I A ) -> Limit A I Γ |
| 365 alimit : ( Γ : Functor I A ) (a0 : Obj A ) ( t0 : NTrans I A ( K A I a0 ) Γ ) -> IsLimit A I Γ a0 t0 | |
| 440 | 366 |
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367 -- product : (a b : Obj A) -> Obj A |
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368 -- π1 : (a b : Obj A) -> Hom A (product a b ) a |
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369 -- π2 : (a b : Obj A) -> Hom A (product a b ) b |
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370 -- isProduct : (a b : Obj A) -> Product A a b (product a b) (π1 a b ) (π2 a b) |
| 440 | 371 |
| 372 equalizer-p : {a b : Obj A} (f g : Hom A a b) -> Obj A | |
| 373 equalizer-e : {a b : Obj A} (f g : Hom A a b) -> Hom A (equalizer-p f g) a | |
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374 isEqualizer : {a b : Obj A} (f g : Hom A a b) -> IsEqualizer A (equalizer-e f g) f g |
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375 open Limit |
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376 limit-c : ( Γ : Functor I A ) -> Obj A |
| 487 | 377 limit-c Γ = a0 ( climit Γ) |
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378 limit-u : ( Γ : Functor I A ) -> NTrans I A ( K A I (limit-c Γ )) Γ |
| 487 | 379 limit-u Γ = t0 ( climit Γ) |
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380 |