comparison applicative.agda @ 768:9bcdbfbaaa39

clean up
author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Tue, 12 Dec 2017 10:25:59 +0900
parents monoidal.agda@c30ca91f3a76
children 43138aead09b
comparison
equal deleted inserted replaced
767:0f8e3b962c13 768:9bcdbfbaaa39
1 open import Level
2 open import Category
3 module applicative where
4
5 open import Data.Product renaming (_×_ to _*_)
6 open import Category.Constructions.Product
7 open import HomReasoning
8 open import cat-utility
9 open import Relation.Binary.Core
10 open import Relation.Binary
11 open import monoidal
12 open import Category.Sets
13 import Relation.Binary.PropositionalEquality
14
15 open Functor
16
17
18 _・_ : {c₁ : Level} { a b c : Obj (Sets {c₁} ) } → (b → c) → (a → b) → a → c
19 _・_ f g = λ x → f ( g x )
20
21 record IsApplicative {c₁ : Level} ( F : Functor (Sets {c₁}) (Sets {c₁}) )
22 ( pure : {a : Obj Sets} → Hom Sets a ( FObj F a ) )
23 ( _<*>_ : {a b : Obj Sets} → FObj F ( a → b ) → FObj F a → FObj F b )
24 : Set (suc (suc c₁)) where
25 field
26 identity : { a : Obj Sets } { u : FObj F a } → pure ( id1 Sets a ) <*> u ≡ u
27 composition : { a b c : Obj Sets } { u : FObj F ( b → c ) } { v : FObj F (a → b ) } { w : FObj F a }
28 → (( pure _・_ <*> u ) <*> v ) <*> w ≡ u <*> (v <*> w)
29 homomorphism : { a b : Obj Sets } { f : Hom Sets a b } { x : a } → pure f <*> pure x ≡ pure (f x)
30 interchange : { a b : Obj Sets } { u : FObj F ( a → b ) } { x : a } → u <*> pure x ≡ pure (λ f → f x) <*> u
31 -- from http://www.staff.city.ac.uk/~ross/papers/Applicative.pdf
32
33 record Applicative {c₁ : Level} ( F : Functor (Sets {c₁}) (Sets {c₁}) )
34 : Set (suc (suc c₁)) where
35 field
36 pure : {a : Obj Sets} → Hom Sets a ( FObj F a )
37 <*> : {a b : Obj Sets} → FObj F ( a → b ) → FObj F a → FObj F b
38 isApplicative : IsApplicative F pure <*>
39
40 ------
41 --
42 -- Appllicative Functor is a Monoidal Functor
43 --
44
45 Applicative→Monoidal : {c : Level} ( F : Functor (Sets {c}) (Sets {c}) ) → (mf : Applicative F )
46 → IsApplicative F ( Applicative.pure mf ) ( Applicative.<*> mf )
47 → MonoidalFunctor {_} {c} {_} {Sets} {Sets} MonoidalSets MonoidalSets
48 Applicative→Monoidal {l} F mf ismf = record {
49 MF = F
50 ; ψ = λ x → unit
51 ; isMonodailFunctor = record {
52 φab = record { TMap = λ x → φ ; isNTrans = record { commute = comm0 } }
53 ; associativity = λ {a b c} → comm1 {a} {b} {c}
54 ; unitarity-idr = λ {a b} → comm2 {a} {b}
55 ; unitarity-idl = λ {a b} → comm3 {a} {b}
56 }
57 } where
58 open Monoidal
59 open IsMonoidal hiding ( _■_ ; _□_ )
60 M = MonoidalSets
61 isM = Monoidal.isMonoidal MonoidalSets
62 unit = Applicative.pure mf OneObj
63 _⊗_ : (x y : Obj Sets ) → Obj Sets
64 _⊗_ x y = (IsMonoidal._□_ (Monoidal.isMonoidal M) ) x y
65 _□_ : {a b c d : Obj Sets } ( f : Hom Sets a c ) ( g : Hom Sets b d ) → Hom Sets ( a ⊗ b ) ( c ⊗ d )
66 _□_ f g = FMap (m-bi M) ( f , g )
67 φ : {x : Obj (Sets × Sets) } → Hom Sets (FObj (Functor● Sets Sets MonoidalSets F) x) (FObj (Functor⊗ Sets Sets MonoidalSets F) x)
68 φ x = Applicative.<*> mf (FMap F (λ j k → (j , k)) (proj₁ x )) (proj₂ x)
69 _<*>_ : {a b : Obj Sets} → FObj F ( a → b ) → FObj F a → FObj F b
70 _<*>_ = Applicative.<*> mf
71 left : {a b : Obj Sets} → {x y : FObj F ( a → b )} → {h : FObj F a } → ( x ≡ y ) → x <*> h ≡ y <*> h
72 left {_} {_} {_} {_} {h} eq = ≡-cong ( λ k → k <*> h ) eq
73 right : {a b : Obj Sets} → {h : FObj F ( a → b )} → {x y : FObj F a } → ( x ≡ y ) → h <*> x ≡ h <*> y
74 right {_} {_} {h} {_} {_} eq = ≡-cong ( λ k → h <*> k ) eq
75 id : { a : Obj Sets } → a → a
76 id x = x
77 pure : {a : Obj Sets } → Hom Sets a ( FObj F a )
78 pure a = Applicative.pure mf a
79 -- special case
80 F→pureid : {a b : Obj Sets } → (x : FObj F a ) → FMap F id x ≡ pure id <*> x
81 F→pureid {a} {b} x = sym ( begin
82 pure id <*> x
83 ≡⟨ IsApplicative.identity ismf ⟩
84 x
85 ≡⟨ ≡-cong ( λ k → k x ) (sym ( IsFunctor.identity (isFunctor F ) )) ⟩ FMap F id x
86 ∎ )
87 where
88 open Relation.Binary.PropositionalEquality
89 open Relation.Binary.PropositionalEquality.≡-Reasoning
90 F→pure : {a b : Obj Sets } → { f : a → b } → {x : FObj F a } → FMap F f x ≡ pure f <*> x
91 F→pure {a} {b} {f} {x} = sym ( begin
92 pure f <*> x
93 ≡⟨ ≡-cong ( λ k → k x ) (UniquenessOfFunctor Sets Sets F ( λ f x → pure f <*> x ) ( extensionality Sets ( λ x → IsApplicative.identity ismf ))) ⟩
94 FMap F f x
95 ∎ )
96 where
97 open Relation.Binary.PropositionalEquality
98 open Relation.Binary.PropositionalEquality.≡-Reasoning
99 p*p : { a b : Obj Sets } { f : Hom Sets a b } { x : a } → pure f <*> pure x ≡ pure (f x)
100 p*p = IsApplicative.homomorphism ismf
101 comp = IsApplicative.composition ismf
102 inter = IsApplicative.interchange ismf
103 pureAssoc : {a b c : Obj Sets } ( f : b → c ) ( g : a → b ) ( h : FObj F a ) → pure f <*> ( pure g <*> h ) ≡ pure ( f ・ g ) <*> h
104 pureAssoc f g h = trans ( trans (sym comp) (left (left p*p) )) ( left p*p )
105 where
106 open Relation.Binary.PropositionalEquality
107 comm00 : {a b : Obj (Sets × Sets)} { f : Hom (Sets × Sets) a b} (x : ( FObj F (proj₁ a) * FObj F (proj₂ a)) ) →
108 (Sets [ FMap (Functor⊗ Sets Sets MonoidalSets F) f o φ ]) x ≡ (Sets [ φ o FMap (Functor● Sets Sets MonoidalSets F) f ]) x
109 comm00 {a} {b} {(f , g)} (x , y) = begin
110 ( FMap (Functor⊗ Sets Sets MonoidalSets F) (f , g) ) ( φ (x , y) )
111 ≡⟨⟩
112 FMap F (λ xy → f (proj₁ xy) , g (proj₂ xy)) ((FMap F (λ j k → j , k) x) <*> y)
113 ≡⟨⟩
114 FMap F (map f g) ((FMap F (λ j k → j , k) x) <*> y)
115 ≡⟨ F→pure ⟩
116 (pure (map f g) <*> (FMap F (λ j k → j , k) x <*> y))
117 ≡⟨ right ( left F→pure ) ⟩
118 (pure (map f g)) <*> ((pure (λ j k → j , k) <*> x) <*> y)
119 ≡⟨ sym ( IsApplicative.composition ismf ) ⟩
120 (( pure _・_ <*> (pure (map f g))) <*> (pure (λ j k → j , k) <*> x)) <*> y
121 ≡⟨ left ( sym ( IsApplicative.composition ismf )) ⟩
122 ((( pure _・_ <*> (( pure _・_ <*> (pure (map f g))))) <*> pure (λ j k → j , k)) <*> x) <*> y
123 ≡⟨ trans ( trans (left ( left (left (right p*p )))) ( left ( left ( left p*p)))) (left (left p*p)) ⟩
124 (pure (( _・_ (( _・_ ((map f g))))) (λ j k → j , k)) <*> x) <*> y
125 ≡⟨⟩
126 (pure (λ j k → f j , g k) <*> x) <*> y
127 ≡⟨⟩
128 ( pure ((_・_ (( _・_ ( ( λ h → h g ))) ( _・_ ))) ((λ j k → f j , k))) <*> x ) <*> y
129 ≡⟨ sym ( trans (left (left (left p*p))) (left ( left p*p)) ) ⟩
130 ((((pure _・_ <*> pure ((λ h → h g) ・ _・_)) <*> pure (λ j k → f j , k)) <*> x) <*> y)
131 ≡⟨ sym (trans ( left ( left ( left (right (left p*p) )))) (left ( left (left (right p*p ))))) ⟩
132 (((pure _・_ <*> (( pure _・_ <*> ( pure ( λ h → h g ))) <*> ( pure _・_ ))) <*> (pure (λ j k → f j , k))) <*> x ) <*> y
133 ≡⟨ left ( ( IsApplicative.composition ismf )) ⟩
134 ((( pure _・_ <*> ( pure ( λ h → h g ))) <*> ( pure _・_ )) <*> (pure (λ j k → f j , k) <*> x )) <*> y
135 ≡⟨ left (IsApplicative.composition ismf ) ⟩
136 ( pure ( λ h → h g ) <*> ( pure _・_ <*> (pure (λ j k → f j , k) <*> x )) ) <*> y
137 ≡⟨ left (sym (IsApplicative.interchange ismf )) ⟩
138 (( pure _・_ <*> (pure (λ j k → f j , k) <*> x )) <*> pure g) <*> y
139 ≡⟨ IsApplicative.composition ismf ⟩
140 (pure (λ j k → f j , k) <*> x) <*> (pure g <*> y)
141 ≡⟨ sym ( trans (left F→pure ) ( right F→pure ) ) ⟩
142 (FMap F (λ j k → f j , k) x) <*> (FMap F g y)
143 ≡⟨ ≡-cong ( λ k → k x <*> (FMap F g y)) ( IsFunctor.distr (isFunctor F )) ⟩
144 (FMap F (λ j k → j , k) (FMap F f x)) <*> (FMap F g y)
145 ≡⟨⟩
146 φ ( ( FMap (Functor● Sets Sets MonoidalSets F) (f , g) ) ( x , y ) )
147
148 where
149 open Relation.Binary.PropositionalEquality
150 open Relation.Binary.PropositionalEquality.≡-Reasoning
151 comm0 : {a b : Obj (Sets × Sets)} { f : Hom (Sets × Sets) a b} → Sets [ Sets [ FMap (Functor⊗ Sets Sets MonoidalSets F) f o φ ]
152 ≈ Sets [ φ o FMap (Functor● Sets Sets MonoidalSets F) f ] ]
153 comm0 {a} {b} {f} = extensionality Sets ( λ (x : ( FObj F (proj₁ a) * FObj F (proj₂ a)) ) → comm00 x )
154 comm10 : {a b c : Obj Sets} → (x : ((FObj F a ⊗ FObj F b) ⊗ FObj F c) ) → (Sets [ φ o Sets [ id1 Sets (FObj F a) □ φ o Iso.≅→ (mα-iso isM) ] ]) x ≡
155 (Sets [ FMap F (Iso.≅→ (mα-iso isM)) o Sets [ φ o φ □ id1 Sets (FObj F c) ] ]) x
156 comm10 {x} {y} {f} ((a , b) , c ) = begin
157 φ (( id □ φ ) ( ( Iso.≅→ (mα-iso isM) ) ((a , b) , c)))
158 ≡⟨⟩
159 (FMap F (λ j k → j , k) a) <*> ( (FMap F (λ j k → j , k) b) <*> c)
160 ≡⟨ trans (left F→pure) (right (left F→pure) ) ⟩
161 (pure (λ j k → j , k) <*> a) <*> ( (pure (λ j k → j , k) <*> b) <*> c)
162 ≡⟨ sym comp ⟩
163 ( ( pure _・_ <*> (pure (λ j k → j , k) <*> a)) <*> (pure (λ j k → j , k) <*> b)) <*> c
164 ≡⟨ sym ( left comp ) ⟩
165 (( ( pure _・_ <*> ( pure _・_ <*> (pure (λ j k → j , k) <*> a))) <*> (pure (λ j k → j , k))) <*> b) <*> c
166 ≡⟨ sym ( left ( left ( left (right comp )))) ⟩
167 (( ( pure _・_ <*> (( (pure _・_ <*> pure _・_ ) <*> (pure (λ j k → j , k))) <*> a)) <*> (pure (λ j k → j , k))) <*> b) <*> c
168 ≡⟨ trans (left ( left (left ( right (left ( left p*p )))))) (left ( left ( left (right (left p*p))))) ⟩
169 (( ( pure _・_ <*> ((pure ((_・_ ( _・_ )) ((λ j k → j , k)))) <*> a)) <*> (pure (λ j k → j , k))) <*> b) <*> c
170 ≡⟨ sym (left ( left ( left comp ) )) ⟩
171 (((( ( pure _・_ <*> (pure _・_ )) <*> (pure ((_・_ ( _・_ )) ((λ j k → j , k))))) <*> a) <*> (pure (λ j k → j , k))) <*> b) <*> c
172 ≡⟨ trans (left ( left ( left (left (left p*p))))) (left ( left ( left (left p*p )))) ⟩
173 ((((pure ( ( _・_ (_・_ )) (((_・_ ( _・_ )) ((λ j k → j , k)))))) <*> a) <*> (pure (λ j k → j , k))) <*> b) <*> c
174 ≡⟨⟩
175 ((((pure (λ f g x y → f , g x y)) <*> a) <*> (pure (λ j k → j , k))) <*> b) <*> c
176 ≡⟨ left ( left inter ) ⟩
177 (((pure (λ f → f (λ j k → j , k))) <*> ((pure (λ f g x y → f , g x y)) <*> a) ) <*> b) <*> c
178 ≡⟨ sym ( left ( left comp )) ⟩
179 (((( pure _・_ <*> (pure (λ f → f (λ j k → j , k)))) <*> (pure (λ f g x y → f , g x y))) <*> a ) <*> b) <*> c
180 ≡⟨ trans (left ( left (left (left p*p) ))) (left (left (left p*p ) )) ⟩
181 ((pure (( _・_ (λ f → f (λ j k → j , k))) (λ f g x y → f , g x y)) <*> a ) <*> b) <*> c
182 ≡⟨⟩
183 (((pure (λ f g h → f , g , h)) <*> a) <*> b) <*> c
184 ≡⟨⟩
185 ((pure ((_・_ ((_・_ ((_・_ ( (λ abc → proj₁ (proj₁ abc) , proj₂ (proj₁ abc) , proj₂ abc)))))))
186 (( _・_ ( _・_ ((λ j k → j , k)))) (λ j k → j , k))) <*> a) <*> b) <*> c
187 ≡⟨ sym (trans ( left ( left ( left (left (right (right p*p))) ) )) (trans (left (left( left (left (right p*p)))))
188 (trans (left (left (left (left p*p)))) (trans ( left (left (left (right (left (right p*p ))))))
189 (trans (left (left (left (right (left p*p))))) (trans (left (left (left (right p*p)))) (left (left (left p*p)))) ) ) )
190 ) ) ⟩
191 ((((pure _・_ <*> ((pure _・_ <*> ((pure _・_ <*> ( pure (λ abc → proj₁ (proj₁ abc) , proj₂ (proj₁ abc) , proj₂ abc))))))) <*>
192 (( pure _・_ <*> ( pure _・_ <*> (pure (λ j k → j , k)))) <*> pure (λ j k → j , k))) <*> a) <*> b) <*> c
193 ≡⟨ left (left comp ) ⟩
194 (((pure _・_ <*> ((pure _・_ <*> ( pure (λ abc → proj₁ (proj₁ abc) , proj₂ (proj₁ abc) , proj₂ abc))))) <*>
195 ((( pure _・_ <*> ( pure _・_ <*> (pure (λ j k → j , k)))) <*> pure (λ j k → j , k)) <*> a)) <*> b) <*> c
196 ≡⟨ left comp ⟩
197 ((pure _・_ <*> ( pure (λ abc → proj₁ (proj₁ abc) , proj₂ (proj₁ abc) , proj₂ abc))) <*>
198 (((( pure _・_ <*> ( pure _・_ <*> (pure (λ j k → j , k)))) <*> pure (λ j k → j , k)) <*> a) <*> b)) <*> c
199 ≡⟨ left ( right (left comp )) ⟩
200 ((pure _・_ <*> ( pure (λ abc → proj₁ (proj₁ abc) , proj₂ (proj₁ abc) , proj₂ abc))) <*>
201 ((( pure _・_ <*> (pure (λ j k → j , k))) <*> (pure (λ j k → j , k) <*> a)) <*> b)) <*> c
202 ≡⟨ left ( right comp ) ⟩
203 ((pure _・_ <*> ( pure (λ abc → proj₁ (proj₁ abc) , proj₂ (proj₁ abc) , proj₂ abc))) <*>
204 (pure (λ j k → j , k) <*> ( (pure (λ j k → j , k) <*> a) <*> b))) <*> c
205 ≡⟨ comp ⟩
206 pure (λ abc → proj₁ (proj₁ abc) , proj₂ (proj₁ abc) , proj₂ abc) <*> ( (pure (λ j k → j , k) <*> ( (pure (λ j k → j , k) <*> a) <*> b)) <*> c)
207 ≡⟨ sym ( trans ( trans F→pure (right (left F→pure ))) ( right ( left (right (left F→pure ))))) ⟩
208 FMap F (λ abc → proj₁ (proj₁ abc) , proj₂ (proj₁ abc) , proj₂ abc) ( (FMap F (λ j k → j , k) ( (FMap F (λ j k → j , k) a) <*> b)) <*> c)
209 ≡⟨⟩
210 ( FMap F (Iso.≅→ (mα-iso isM))) (φ (( φ □ id1 Sets (FObj F f) ) ((a , b) , c)))
211
212 where
213 open Relation.Binary.PropositionalEquality
214 open Relation.Binary.PropositionalEquality.≡-Reasoning
215 comm1 : {a b c : Obj Sets} → Sets [ Sets [ φ
216 o Sets [ (id1 Sets (FObj F a) □ φ ) o Iso.≅→ (mα-iso isM) ] ]
217 ≈ Sets [ FMap F (Iso.≅→ (mα-iso isM)) o Sets [ φ o (φ □ id1 Sets (FObj F c)) ] ] ]
218 comm1 {a} {b} {c} = extensionality Sets ( λ x → comm10 x )
219 comm20 : {a b : Obj Sets} ( x : FObj F a * One ) → ( Sets [
220 FMap F (Iso.≅→ (mρ-iso isM)) o Sets [ φ o
221 FMap (m-bi MonoidalSets) (id1 Sets (FObj F a) , (λ _ → unit )) ] ] ) x ≡ Iso.≅→ (mρ-iso isM) x
222 comm20 {a} {b} (x , OneObj ) = begin
223 (FMap F (Iso.≅→ (mρ-iso isM))) ( φ (( FMap (m-bi MonoidalSets) (id1 Sets (FObj F a) , (λ _ → unit))) (x , OneObj) ))
224 ≡⟨⟩
225 FMap F proj₁ ((FMap F (λ j k → j , k) x) <*> (pure OneObj))
226 ≡⟨ ≡-cong ( λ k → FMap F proj₁ k) ( IsApplicative.interchange ismf ) ⟩
227 FMap F proj₁ ((pure (λ f → f OneObj)) <*> (FMap F (λ j k → j , k) x))
228 ≡⟨ ( trans F→pure (right ( right F→pure )) ) ⟩
229 pure proj₁ <*> ((pure (λ f → f OneObj)) <*> (pure (λ j k → j , k) <*> x))
230 ≡⟨ sym ( right comp ) ⟩
231 pure proj₁ <*> (((pure _・_ <*> (pure (λ f → f OneObj))) <*> pure (λ j k → j , k)) <*> x)
232 ≡⟨ sym comp ⟩
233 ( ( pure _・_ <*> (pure proj₁ ) ) <*> ((pure _・_ <*> (pure (λ f → f OneObj))) <*> pure (λ j k → j , k))) <*> x
234 ≡⟨ trans ( trans ( trans ( left ( left p*p)) ( left ( right (left p*p) ))) (left (right p*p) ) ) (left p*p) ⟩
235 pure ( ( _・_ (proj₁ {l} {l})) ((_・_ ((λ f → f OneObj))) (λ j k → j , k))) <*> x
236 ≡⟨⟩
237 pure id <*> x
238 ≡⟨ IsApplicative.identity ismf ⟩
239 x
240 ≡⟨⟩
241 Iso.≅→ (mρ-iso isM) (x , OneObj)
242
243 where
244 open Relation.Binary.PropositionalEquality
245 open Relation.Binary.PropositionalEquality.≡-Reasoning
246 comm2 : {a b : Obj Sets} → Sets [ Sets [
247 FMap F (Iso.≅→ (mρ-iso isM)) o Sets [ φ o
248 FMap (m-bi MonoidalSets) (id1 Sets (FObj F a) , (λ _ → unit )) ] ] ≈ Iso.≅→ (mρ-iso isM) ]
249 comm2 {a} {b} = extensionality Sets ( λ x → comm20 {a} {b} x )
250 comm30 : {a b : Obj Sets} ( x : One * FObj F b ) → ( Sets [
251 FMap F (Iso.≅→ (mλ-iso isM)) o Sets [ φ o
252 FMap (m-bi MonoidalSets) ((λ _ → unit ) , id1 Sets (FObj F b) ) ] ] ) x ≡ Iso.≅→ (mλ-iso isM) x
253 comm30 {a} {b} ( OneObj , x) = begin
254 (FMap F (Iso.≅→ (mλ-iso isM))) ( φ ( unit , x ) )
255 ≡⟨⟩
256 FMap F proj₂ ((FMap F (λ j k → j , k) (pure OneObj)) <*> x)
257 ≡⟨ ( trans F→pure (right ( left F→pure )) ) ⟩
258 pure proj₂ <*> ((pure (λ j k → j , k) <*> (pure OneObj)) <*> x)
259 ≡⟨ sym comp ⟩
260 ((pure _・_ <*> (pure proj₂)) <*> (pure (λ j k → j , k) <*> (pure OneObj))) <*> x
261 ≡⟨ trans (trans (left (left p*p )) (left ( right p*p)) ) (left p*p) ⟩
262 pure ((_・_ (proj₂ {l}) )((λ (j : One {l}) (k : b ) → j , k) OneObj)) <*> x
263 ≡⟨⟩
264 pure id <*> x
265 ≡⟨ IsApplicative.identity ismf ⟩
266 x
267 ≡⟨⟩
268 Iso.≅→ (mλ-iso isM) ( OneObj , x )
269
270 where
271 open Relation.Binary.PropositionalEquality
272 open Relation.Binary.PropositionalEquality.≡-Reasoning
273 comm3 : {a b : Obj Sets} → Sets [ Sets [ FMap F (Iso.≅→ (mλ-iso isM)) o
274 Sets [ φ o FMap (m-bi MonoidalSets) ((λ _ → unit ) , id1 Sets (FObj F b)) ] ] ≈ Iso.≅→ (mλ-iso isM) ]
275 comm3 {a} {b} = extensionality Sets ( λ x → comm30 {a} {b} x )
276
277 ----
278 --
279 -- Monoidal laws imples Applicative laws
280 --
281
282 HaskellMonoidal→Applicative : {c₁ : Level} ( F : Functor (Sets {c₁}) (Sets {c₁}) )
283 ( Mono : HaskellMonoidalFunctor F )
284 → Applicative F
285 HaskellMonoidal→Applicative {c₁} F Mono = record {
286 pure = pure ;
287 <*> = _<*>_ ;
288 isApplicative = record {
289 identity = identity
290 ; composition = composition
291 ; homomorphism = homomorphism
292 ; interchange = interchange
293 }
294 }
295 where
296 unit : FObj F One
297 unit = HaskellMonoidalFunctor.unit Mono
298 φ : {a b : Obj Sets} → Hom Sets ((FObj F a) * (FObj F b )) ( FObj F ( a * b ) )
299 φ = HaskellMonoidalFunctor.φ Mono
300 mono : IsHaskellMonoidalFunctor F unit φ
301 mono = HaskellMonoidalFunctor.isHaskellMonoidalFunctor Mono
302 id : { a : Obj Sets } → a → a
303 id x = x
304 isM : IsMonoidal (Sets {c₁}) One SetsTensorProduct
305 isM = Monoidal.isMonoidal MonoidalSets
306 pure : {a : Obj Sets} → Hom Sets a ( FObj F a )
307 pure {a} x = FMap F ( λ y → x ) (unit )
308 _<*>_ : {a b : Obj Sets} → FObj F ( a → b ) → FObj F a → FObj F b
309 _<*>_ {a} {b} x y = FMap F ( λ r → ( proj₁ r ) ( proj₂ r ) ) (φ ( x , y ))
310 -- right does not work right it makes yellows. why?
311 -- right : {n : Level} { a b : Set n} → { x y : a } { h : a → b } → ( x ≡ y ) → h x ≡ h y
312 -- right {_} {_} {_} {_} {_} {h} eq = ≡-cong ( λ k → h k ) eq
313 left : {n : Level} { a b : Set n} → { x y : a → b } { h : a } → ( x ≡ y ) → x h ≡ y h
314 left {_} {_} {_} {_} {_} {h} eq = ≡-cong ( λ k → k h ) eq
315 open Relation.Binary.PropositionalEquality
316 FφF→F : { a b c d e : Obj Sets } { g : Hom Sets a c } { h : Hom Sets b d }
317 { f : Hom Sets (c * d) e }
318 { x : FObj F a } { y : FObj F b }
319 → FMap F f ( φ ( FMap F g x , FMap F h y ) ) ≡ FMap F ( f o map g h ) ( φ ( x , y ) )
320 FφF→F {a} {b} {c} {d} {e} {g} {h} {f} {x} {y} = sym ( begin
321 FMap F ( f o map g h ) ( φ ( x , y ) )
322 ≡⟨ ≡-cong ( λ k → k ( φ ( x , y ))) ( IsFunctor.distr (isFunctor F) ) ⟩
323 FMap F f (( FMap F ( map g h ) ) ( φ ( x , y )))
324 ≡⟨ ≡-cong ( λ k → FMap F f k ) ( IsHaskellMonoidalFunctor.natφ mono ) ⟩
325 FMap F f ( φ ( FMap F g x , FMap F h y ) )
326 ∎ )
327 where
328 open Relation.Binary.PropositionalEquality.≡-Reasoning
329 u→F : {a : Obj Sets } {u : FObj F a} → u ≡ FMap F id u
330 u→F {a} {u} = sym ( ≡-cong ( λ k → k u ) ( IsFunctor.identity ( isFunctor F ) ) )
331 φunitr : {a : Obj Sets } {u : FObj F a} → φ ( unit , u) ≡ FMap F (Iso.≅← (IsMonoidal.mλ-iso isM)) u
332 φunitr {a} {u} = sym ( begin
333 FMap F (Iso.≅← (IsMonoidal.mλ-iso isM)) u
334 ≡⟨ ≡-cong ( λ k → FMap F (Iso.≅← (IsMonoidal.mλ-iso isM)) k ) (sym (IsHaskellMonoidalFunctor.idlφ mono)) ⟩
335 FMap F (Iso.≅← (IsMonoidal.mλ-iso isM)) ( FMap F (Iso.≅→ (IsMonoidal.mλ-iso isM)) ( φ ( unit , u) ) )
336 ≡⟨ left ( sym ( IsFunctor.distr ( isFunctor F ) )) ⟩
337 (FMap F ( (Iso.≅← (IsMonoidal.mλ-iso isM)) o (Iso.≅→ (IsMonoidal.mλ-iso isM)))) ( φ ( unit , u) )
338 ≡⟨ ≡-cong ( λ k → FMap F k ( φ ( unit , u) )) (Iso.iso→ ( (IsMonoidal.mλ-iso isM) )) ⟩
339 FMap F id ( φ ( unit , u) )
340 ≡⟨ left ( IsFunctor.identity ( isFunctor F ) ) ⟩
341 id ( φ ( unit , u) )
342 ≡⟨⟩
343 φ ( unit , u)
344 ∎ )
345 where
346 open Relation.Binary.PropositionalEquality.≡-Reasoning
347 φunitl : {a : Obj Sets } {u : FObj F a} → φ ( u , unit ) ≡ FMap F (Iso.≅← (IsMonoidal.mρ-iso isM)) u
348 φunitl {a} {u} = sym ( begin
349 FMap F (Iso.≅← (IsMonoidal.mρ-iso isM)) u
350 ≡⟨ ≡-cong ( λ k → FMap F (Iso.≅← (IsMonoidal.mρ-iso isM)) k ) (sym (IsHaskellMonoidalFunctor.idrφ mono)) ⟩
351 FMap F (Iso.≅← (IsMonoidal.mρ-iso isM)) ( FMap F (Iso.≅→ (IsMonoidal.mρ-iso isM)) ( φ ( u , unit ) ) )
352 ≡⟨ left ( sym ( IsFunctor.distr ( isFunctor F ) )) ⟩
353 (FMap F ( (Iso.≅← (IsMonoidal.mρ-iso isM)) o (Iso.≅→ (IsMonoidal.mρ-iso isM)))) ( φ ( u , unit ) )
354 ≡⟨ ≡-cong ( λ k → FMap F k ( φ ( u , unit ) )) (Iso.iso→ ( (IsMonoidal.mρ-iso isM) )) ⟩
355 FMap F id ( φ ( u , unit ) )
356 ≡⟨ left ( IsFunctor.identity ( isFunctor F ) ) ⟩
357 id ( φ ( u , unit ) )
358 ≡⟨⟩
359 φ ( u , unit )
360 ∎ )
361 where
362 open Relation.Binary.PropositionalEquality.≡-Reasoning
363 open IsMonoidal
364 identity : { a : Obj Sets } { u : FObj F a } → pure ( id1 Sets a ) <*> u ≡ u
365 identity {a} {u} = begin
366 pure id <*> u
367 ≡⟨⟩
368 ( FMap F ( λ r → ( proj₁ r ) ( proj₂ r )) ) ( φ ( FMap F ( λ y → id ) unit , u ) )
369 ≡⟨ ≡-cong ( λ k → ( FMap F ( λ r → ( proj₁ r ) ( proj₂ r )) ) ( φ ( FMap F ( λ y → id ) unit , k ))) u→F ⟩
370 ( FMap F ( λ r → ( proj₁ r ) ( proj₂ r )) ) ( φ ( FMap F ( λ y → id ) unit , FMap F id u ) )
371 ≡⟨ FφF→F ⟩
372 FMap F (λ x → proj₂ x ) (φ (unit , u ) )
373 ≡⟨⟩
374 FMap F (Iso.≅→ (mλ-iso isM)) (φ (unit , u ))
375 ≡⟨ IsHaskellMonoidalFunctor.idlφ mono ⟩
376 u
377
378 where
379 open Relation.Binary.PropositionalEquality.≡-Reasoning
380 composition : { a b c : Obj Sets } { u : FObj F ( b → c ) } { v : FObj F (a → b ) } { w : FObj F a }
381 → (( pure _・_ <*> u ) <*> v ) <*> w ≡ u <*> (v <*> w)
382 composition {a} {b} {c} {u} {v} {w} = begin
383 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ r → proj₁ r (proj₂ r)) (φ
384 (FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ y f g x → f (g x)) unit , u)) , v)) , w))
385 ≡⟨ ≡-cong ( λ k → FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ y f g x → f (g x)) unit , k)) , v)) , w)) ) u→F ⟩
386 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ r → proj₁ r (proj₂ r)) (φ
387 (FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ y f g x → f (g x)) unit , FMap F id u )) , v)) , w))
388 ≡⟨ ≡-cong ( λ k → FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ r → proj₁ r (proj₂ r)) (φ ( k , v)) , w)) ) FφF→F ⟩
389 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ r → proj₁ r (proj₂ r)) (φ
390 (FMap F ( λ x → (λ r → proj₁ r (proj₂ r)) ((map (λ y f g x → f (g x)) id ) x)) (φ ( unit , u)) , v)) , w))
391 ≡⟨ ≡-cong ( λ k → ( FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ r → proj₁ r (proj₂ r)) (φ
392 (FMap F ( λ x → (λ r → proj₁ r (proj₂ r)) ((map (λ y f g x → f (g x)) id ) x)) k , v)) , w)) ) ) φunitr ⟩
393 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ r → proj₁ r (proj₂ r)) (φ
394 ( (FMap F ( λ x → (λ r → proj₁ r (proj₂ r)) ((map (λ y f g x → f (g x)) id ) x)) (FMap F (Iso.≅← (mλ-iso isM)) u) ) , v)) , w))
395 ≡⟨ ≡-cong ( λ k → FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ r → proj₁ r (proj₂ r)) (φ
396 (k u , v)) , w)) ) (sym ( IsFunctor.distr (isFunctor F ))) ⟩
397 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ r → proj₁ r (proj₂ r)) (φ
398 ( FMap F (λ x → ((λ y f g x₁ → f (g x₁)) unit x) ) u , v)) , w))
399 ≡⟨⟩
400 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ r → proj₁ r (proj₂ r)) (φ
401 ( FMap F (λ x g h → x (g h) ) u , v)) , w))
402 ≡⟨ ≡-cong ( λ k → FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ r → proj₁ r (proj₂ r)) (φ ( FMap F (λ x g h → x (g h) ) u , k)) , w)) ) u→F ⟩
403 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ x g h → x (g h)) u , FMap F id v)) , w))
404 ≡⟨ ≡-cong ( λ k → FMap F (λ r → proj₁ r (proj₂ r)) (φ (k , w)) ) FφF→F ⟩
405 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F ((λ r → proj₁ r (proj₂ r)) o map (λ x g h → x (g h)) id) (φ (u , v)) , w))
406 ≡⟨⟩
407 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ x h → proj₁ x (proj₂ x h)) (φ (u , v)) , w))
408 ≡⟨ ≡-cong ( λ k → FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ x h → proj₁ x (proj₂ x h)) (φ (u , v)) , k)) ) u→F ⟩
409 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ x h → proj₁ x (proj₂ x h)) (φ (u , v)) , FMap F id w))
410 ≡⟨ FφF→F ⟩
411 FMap F ((λ r → proj₁ r (proj₂ r)) o map (λ x h → proj₁ x (proj₂ x h)) id) (φ (φ (u , v) , w))
412 ≡⟨⟩
413 FMap F (λ x → proj₁ (proj₁ x) (proj₂ (proj₁ x) (proj₂ x))) (φ (φ (u , v) , w))
414 ≡⟨ ≡-cong ( λ k → FMap F (λ x → proj₁ (proj₁ x) (proj₂ (proj₁ x) (proj₂ x))) (k (φ (φ (u , v) , w)) )) (sym (IsFunctor.identity (isFunctor F ))) ⟩
415 FMap F (λ x → proj₁ (proj₁ x) (proj₂ (proj₁ x) (proj₂ x))) (FMap F id (φ (φ (u , v) , w)) )
416 ≡⟨ ≡-cong ( λ k → FMap F (λ x → proj₁ (proj₁ x) (proj₂ (proj₁ x) (proj₂ x))) (FMap F k (φ (φ (u , v) , w)) ) ) (sym (Iso.iso→ (mα-iso isM))) ⟩
417 FMap F (λ x → proj₁ (proj₁ x) (proj₂ (proj₁ x) (proj₂ x))) (FMap F ( (Iso.≅← (mα-iso isM)) o (Iso.≅→ (mα-iso isM))) (φ (φ (u , v) , w)) )
418 ≡⟨ ≡-cong ( λ k → FMap F (λ x → proj₁ (proj₁ x) (proj₂ (proj₁ x) (proj₂ x))) (k (φ (φ (u , v) , w)))) ( IsFunctor.distr (isFunctor F )) ⟩
419 FMap F (λ x → proj₁ (proj₁ x) (proj₂ (proj₁ x) (proj₂ x))) (FMap F (Iso.≅← (mα-iso isM)) ( FMap F (Iso.≅→ (mα-iso isM)) (φ (φ (u , v) , w)) ))
420 ≡⟨ ≡-cong ( λ k → FMap F (λ x → proj₁ (proj₁ x) (proj₂ (proj₁ x) (proj₂ x))) (FMap F (Iso.≅← (mα-iso isM)) k) ) (sym ( IsHaskellMonoidalFunctor.assocφ mono ) ) ⟩
421 FMap F (λ x → proj₁ (proj₁ x) (proj₂ (proj₁ x) (proj₂ x))) (FMap F (Iso.≅← (mα-iso isM)) (φ (u , φ (v , w))))
422 ≡⟨⟩
423 FMap F (λ x → proj₁ (proj₁ x) (proj₂ (proj₁ x) (proj₂ x))) (FMap F (λ r → (proj₁ r , proj₁ (proj₂ r)) , proj₂ (proj₂ r)) (φ (u , φ (v , w))))
424 ≡⟨ left (sym ( IsFunctor.distr (isFunctor F ))) ⟩
425 FMap F (λ y → (λ x → proj₁ (proj₁ x) (proj₂ (proj₁ x) (proj₂ x))) ((λ r → (proj₁ r , proj₁ (proj₂ r)) , proj₂ (proj₂ r)) y )) (φ (u , φ (v , w)))
426 ≡⟨⟩
427 FMap F (λ y → proj₁ y (proj₁ (proj₂ y) (proj₂ (proj₂ y)))) (φ (u , φ (v , w)))
428 ≡⟨⟩
429 FMap F ( λ x → (proj₁ x) ((λ r → proj₁ r (proj₂ r)) ( proj₂ x))) ( φ ( u , (φ (v , w))))
430 ≡⟨ sym FφF→F ⟩
431 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F id u , FMap F (λ r → proj₁ r (proj₂ r)) (φ (v , w))))
432 ≡⟨ ≡-cong ( λ k → FMap F (λ r → proj₁ r (proj₂ r)) (φ (k , FMap F (λ r → proj₁ r (proj₂ r)) (φ (v , w)))) ) (sym u→F ) ⟩
433 FMap F (λ r → proj₁ r (proj₂ r)) (φ (u , FMap F (λ r → proj₁ r (proj₂ r)) (φ (v , w))))
434
435 where
436 open Relation.Binary.PropositionalEquality.≡-Reasoning
437 homomorphism : { a b : Obj Sets } { f : Hom Sets a b } { x : a } → pure f <*> pure x ≡ pure (f x)
438 homomorphism {a} {b} {f} {x} = begin
439 pure f <*> pure x
440 ≡⟨⟩
441 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ y → f) unit , FMap F (λ y → x) unit))
442 ≡⟨ FφF→F ⟩
443 FMap F ((λ r → proj₁ r (proj₂ r)) o map (λ y → f) (λ y → x)) (φ (unit , unit))
444 ≡⟨⟩
445 FMap F (λ y → f x) (φ (unit , unit))
446 ≡⟨ ≡-cong ( λ k → FMap F (λ y → f x) k ) φunitl ⟩
447 FMap F (λ y → f x) (FMap F (Iso.≅← (mρ-iso isM)) unit)
448 ≡⟨⟩
449 FMap F (λ y → f x) (FMap F (λ y → (y , OneObj)) unit)
450 ≡⟨ left ( sym ( IsFunctor.distr (isFunctor F ))) ⟩
451 FMap F (λ y → f x) unit
452 ≡⟨⟩
453 pure (f x)
454
455 where
456 open Relation.Binary.PropositionalEquality.≡-Reasoning
457 interchange : { a b : Obj Sets } { u : FObj F ( a → b ) } { x : a } → u <*> pure x ≡ pure (λ f → f x) <*> u
458 interchange {a} {b} {u} {x} = begin
459 u <*> pure x
460 ≡⟨⟩
461 FMap F (λ r → proj₁ r (proj₂ r)) (φ (u , FMap F (λ y → x) unit))
462 ≡⟨ ≡-cong ( λ k → FMap F (λ r → proj₁ r (proj₂ r)) (φ (k , FMap F (λ y → x) unit)) ) u→F ⟩
463 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F id u , FMap F (λ y → x) unit))
464 ≡⟨ FφF→F ⟩
465 FMap F ((λ r → proj₁ r (proj₂ r)) o map id (λ y → x)) (φ (u , unit))
466 ≡⟨⟩
467 FMap F (λ r → proj₁ r x) (φ (u , unit))
468 ≡⟨ ≡-cong ( λ k → FMap F (λ r → proj₁ r x) k ) φunitl ⟩
469 FMap F (λ r → proj₁ r x) (( FMap F (Iso.≅← (mρ-iso isM))) u )
470 ≡⟨ left ( sym ( IsFunctor.distr (isFunctor F )) ) ⟩
471 FMap F (( λ r → proj₁ r x) o ((Iso.≅← (mρ-iso isM) ))) u
472 ≡⟨⟩
473 FMap F (( λ r → proj₂ r x) o ((Iso.≅← (mλ-iso isM) ))) u
474 ≡⟨ left ( IsFunctor.distr (isFunctor F )) ⟩
475 FMap F (λ r → proj₂ r x) (FMap F (Iso.≅← (IsMonoidal.mλ-iso isM)) u)
476 ≡⟨ ≡-cong ( λ k → FMap F (λ r → proj₂ r x) k ) (sym φunitr ) ⟩
477 FMap F (λ r → proj₂ r x) (φ (unit , u))
478 ≡⟨⟩
479 FMap F ((λ r → proj₁ r (proj₂ r)) o map (λ y f → f x) id) (φ (unit , u))
480 ≡⟨ sym FφF→F ⟩
481 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ y f → f x) unit , FMap F id u))
482 ≡⟨ ≡-cong ( λ k → FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ y f → f x) unit , k)) ) (sym u→F) ⟩
483 FMap F (λ r → proj₁ r (proj₂ r)) (φ (FMap F (λ y f → f x) unit , u))
484 ≡⟨⟩
485 pure (λ f → f x) <*> u
486
487 where
488 open Relation.Binary.PropositionalEquality.≡-Reasoning
489
490 ----
491 --
492 -- Applicative laws imples Monoidal laws
493 --
494
495 Applicative→HaskellMonoidal : {c₁ : Level} ( F : Functor (Sets {c₁}) (Sets {c₁}) )
496 ( App : Applicative F )
497 → HaskellMonoidalFunctor F
498 Applicative→HaskellMonoidal {l} F App = record {
499 unit = unit ;
500 φ = φ ;
501 isHaskellMonoidalFunctor = record {
502 natφ = natφ
503 ; assocφ = assocφ
504 ; idrφ = idrφ
505 ; idlφ = idlφ
506 }
507 } where
508 pure = Applicative.pure App
509 <*> = Applicative.<*> App
510 app = Applicative.isApplicative App
511 unit : FObj F One
512 unit = pure OneObj
513 φ : {a b : Obj Sets} → Hom Sets ((FObj F a) * (FObj F b )) ( FObj F ( a * b ) )
514 φ = λ x → <*> (FMap F (λ j k → (j , k)) ( proj₁ x)) ( proj₂ x)
515 isM : IsMonoidal (Sets {l}) One SetsTensorProduct
516 isM = Monoidal.isMonoidal MonoidalSets
517 MF : MonoidalFunctor {_} {l} {_} {Sets} {Sets} MonoidalSets MonoidalSets
518 MF = Applicative→Monoidal F App app
519 isMF = MonoidalFunctor.isMonodailFunctor MF
520 natφ : { a b c d : Obj Sets } { x : FObj F a} { y : FObj F b} { f : a → c } { g : b → d }
521 → FMap F (map f g) (φ (x , y)) ≡ φ (FMap F f x , FMap F g y)
522 natφ {a} {b} {c} {d} {x} {y} {f} {g} = begin
523 FMap F (map f g) (φ (x , y))
524 ≡⟨⟩
525 FMap F (λ xy → f (proj₁ xy) , g (proj₂ xy)) (<*> (FMap F (λ j k → j , k) x) y)
526 ≡⟨ ≡-cong ( λ h → h (x , y)) ( IsNTrans.commute ( NTrans.isNTrans ( IsMonoidalFunctor.φab isMF ))) ⟩
527 <*> (FMap F (λ j k → j , k) (FMap F f x)) (FMap F g y)
528 ≡⟨⟩
529 φ (FMap F f x , FMap F g y)
530
531 where
532 open Relation.Binary.PropositionalEquality.≡-Reasoning
533 assocφ : { x y z : Obj Sets } { a : FObj F x } { b : FObj F y }{ c : FObj F z }
534 → φ (a , φ (b , c)) ≡ FMap F (Iso.≅→ (IsMonoidal.mα-iso isM)) (φ (φ (a , b) , c))
535 assocφ {x} {y} {z} {a} {b} {c} = ≡-cong ( λ h → h ((a , b) , c ) ) ( IsMonoidalFunctor.associativity isMF )
536 idrφ : {a : Obj Sets } { x : FObj F a } → FMap F (Iso.≅→ (IsMonoidal.mρ-iso isM)) (φ (x , unit)) ≡ x
537 idrφ {a} {x} = ≡-cong ( λ h → h (x , OneObj ) ) ( IsMonoidalFunctor.unitarity-idr isMF {a} {One} )
538 idlφ : {a : Obj Sets } { x : FObj F a } → FMap F (Iso.≅→ (IsMonoidal.mλ-iso isM)) (φ (unit , x)) ≡ x
539 idlφ {a} {x} = ≡-cong ( λ h → h (OneObj , x ) ) ( IsMonoidalFunctor.unitarity-idl isMF {One} {a} )
540
541