summaryrefslogtreecommitdiff
path: root/src/Helium/Semantics/Axiomatic/Assertion.agda
blob: 70feb2bee938e6b92792655b31146c6f343b0c98 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
------------------------------------------------------------------------
-- Agda Helium
--
-- Definition of assertions used in correctness triples
------------------------------------------------------------------------

{-# OPTIONS --safe --without-K #-}

open import Helium.Data.Pseudocode.Types using (RawPseudocode)

module Helium.Semantics.Axiomatic.Assertion
  {b₁ b₂ i₁ i₂ i₃ r₁ r₂ r₃}
  (rawPseudocode : RawPseudocode b₁ b₂ i₁ i₂ i₃ r₁ r₂ r₃)
  where

open RawPseudocode rawPseudocode

open import Data.Bool as Bool using (Bool)
open import Data.Fin as Fin using (suc)
open import Data.Fin.Patterns
open import Data.Nat using (ℕ; suc)
open import Data.Product using (proj₁; proj₂)
open import Data.Vec as Vec using (Vec; []; _∷_; _++_)
open import Data.Vec.Relation.Unary.All as All using (All; []; _∷_)
open import Helium.Data.Pseudocode.Core
open import Helium.Semantics.Axiomatic.Core rawPseudocode
open import Helium.Semantics.Axiomatic.Term rawPseudocode as Term using (Term)
open import Level using (_⊔_; lift)
open import Relation.Nullary using (does)

private
  variable
    t t′     : Type
    m n o    : ℕ
    Γ Δ Σ ts : Vec Type m

infixl 7 _[_]↦_

open Term.Term

data Assertion (Σ : Vec Type o) (Γ : Vec Type n) (Δ : Vec Type m) : Set (b₁ ⊔ i₁ ⊔ r₁) where
  _[_]↦_ : ∀ {m t} → Term Σ Γ Δ (asType t m) → Term Σ Γ Δ (fin m) → Term Σ Γ Δ (elemType t) → Assertion Σ Γ Δ
  all    : Assertion Σ Γ (t ∷ Δ) → Assertion Σ Γ Δ
  some   : Assertion Σ Γ (t ∷ Δ) → Assertion Σ Γ Δ
  pred   : Term Σ Γ Δ bool → Assertion Σ Γ Δ
  comb   : ∀ {n} → (Vec Bool n → Bool) → Vec (Assertion Σ Γ Δ) n → Assertion Σ Γ Δ

elimVar : Assertion Σ (t ∷ Γ) Δ → Term Σ Γ Δ t → Assertion Σ Γ Δ
elimVar (ref [ i ]↦ val) t = Term.elimVar ref t [ Term.elimVar i t ]↦ Term.elimVar val t
elimVar (all P)          t = all (elimVar P (Term.wknMeta t))
elimVar (some P)         t = some (elimVar P (Term.wknMeta t))
elimVar (pred p)         t = pred (Term.elimVar p t)
elimVar (comb f Ps)      t = comb f (helper Ps t)
  where
  helper : ∀ {n} → Vec (Assertion Σ (_ ∷ Γ) Δ) n → Term Σ Γ Δ _ → Vec (Assertion Σ Γ Δ) n
  helper []       t = []
  helper (P ∷ Ps) t = elimVar P t ∷ helper Ps t

wknVar : Assertion Σ Γ Δ → Assertion Σ (t ∷ Γ) Δ
wknVar (ref [ i ]↦ val) = Term.wknVar ref [ Term.wknVar i ]↦ Term.wknVar val
wknVar (all P)          = all (wknVar P)
wknVar (some P)         = some (wknVar P)
wknVar (pred p)         = pred (Term.wknVar p)
wknVar (comb f Ps)      = comb f (helper Ps)
  where
  helper : ∀ {n} → Vec (Assertion Σ Γ Δ) n → Vec (Assertion Σ (_ ∷ Γ) Δ) n
  helper []       = []
  helper (P ∷ Ps) = wknVar P ∷ helper Ps

wknVars : (ts : Vec Type n) → Assertion Σ Γ Δ → Assertion Σ (ts ++ Γ) Δ
wknVars τs (ref [ i ]↦ val) = Term.wknVars τs ref [ Term.wknVars τs i ]↦ Term.wknVars τs val
wknVars τs (all P)          = all (wknVars τs P)
wknVars τs (some P)         = some (wknVars τs P)
wknVars τs (pred p)         = pred (Term.wknVars τs p)
wknVars τs (comb f Ps)      = comb f (helper Ps)
  where
  helper : ∀ {n} → Vec (Assertion Σ Γ Δ) n → Vec (Assertion Σ (τs ++ Γ) Δ) n
  helper []       = []
  helper (P ∷ Ps) = wknVars τs P ∷ helper Ps

addVars : Assertion Σ [] Δ → Assertion Σ Γ Δ
addVars (ref [ i ]↦ val) = Term.addVars ref [ Term.addVars i ]↦ Term.addVars val
addVars (all P)          = all (addVars P)
addVars (some P)         = some (addVars P)
addVars (pred p)         = pred (Term.addVars p)
addVars (comb f Ps)      = comb f (helper Ps)
  where
  helper : ∀ {n} → Vec (Assertion Σ [] Δ) n → Vec (Assertion Σ Γ Δ) n
  helper []       = []
  helper (P ∷ Ps) = addVars P ∷ helper Ps

wknMetaAt : ∀ i → Assertion Σ Γ Δ → Assertion Σ Γ (Vec.insert Δ i t)
wknMetaAt i (ref [ j ]↦ val) = Term.wknMetaAt i ref [ Term.wknMetaAt i j ]↦ Term.wknMetaAt i val
wknMetaAt i (all P)          = all (wknMetaAt (suc i) P)
wknMetaAt i (some P)         = some (wknMetaAt (suc i) P)
wknMetaAt i (pred p)         = pred (Term.wknMetaAt i p)
wknMetaAt i (comb f Ps)      = comb f (helper i Ps)
  where
  helper : ∀ {n} i → Vec (Assertion Σ Γ Δ) n → Vec (Assertion Σ Γ (Vec.insert Δ i _)) n
  helper i []       = []
  helper i (P ∷ Ps) = wknMetaAt i P ∷ helper i Ps

-- NOTE: better to induct on P instead of ts?
wknMetas : (ts : Vec Type n) → Assertion Σ Γ Δ → Assertion Σ Γ (ts ++ Δ)
wknMetas []       P = P
wknMetas (_ ∷ ts) P = wknMetaAt 0F (wknMetas ts P)

module _ (2≉0 : Term.2≉0) where
  -- NOTE: better to induct on e here than in Term?
  subst : Assertion Σ Γ Δ → {e : Code.Expression Σ Γ t} → Code.CanAssign Σ e → Term Σ Γ Δ t → Assertion Σ Γ Δ
  subst (ref [ i ]↦ val) e t = Term.subst 2≉0 ref e t [ Term.subst 2≉0 i e t ]↦ Term.subst 2≉0 val e t
  subst (all P)          e t = all (subst P e (Term.wknMeta t))
  subst (some P)         e t = some (subst P e (Term.wknMeta t))
  subst (pred p)         e t = pred (Term.subst 2≉0 p e t)
  subst (comb f Ps)      e t = comb f (helper Ps e t)
    where
    helper : ∀ {t n} → Vec (Assertion Σ Γ Δ) n → {e : Code.Expression Σ Γ t} → Code.CanAssign Σ e → Term Σ Γ Δ t → Vec (Assertion Σ Γ Δ) n
    helper []       e t = []
    helper (P ∷ Ps) e t = subst P e t ∷ helper Ps e t

module Construct where
  infixl 6 _∧_
  infixl 5 _∨_

  true : Assertion Σ Γ Δ
  true = comb (λ _ → Bool.true) []

  false : Assertion Σ Γ Δ
  false = comb (λ _ → Bool.false) []

  _∧_ : Assertion Σ Γ Δ → Assertion Σ Γ Δ → Assertion Σ Γ Δ
  P ∧ Q = comb (λ { (p ∷ q ∷ []) → p Bool.∧ q }) (P ∷ Q ∷ [])

  _∨_ : Assertion Σ Γ Δ → Assertion Σ Γ Δ → Assertion Σ Γ Δ
  P ∨ Q = comb (λ { (p ∷ q ∷ []) → p Bool.∨ q }) (P ∷ Q ∷ [])

  equal : Term Σ Γ Δ t → Term Σ Γ Δ t → Assertion Σ Γ Δ
  equal {t = bool} x y = pred Term.[ bool ][ x ≟ y ]
  equal {t = int} x y = pred Term.[ int ][ x ≟ y ]
  equal {t = fin n} x y = pred Term.[ fin ][ x ≟ y ]
  equal {t = real} x y = pred Term.[ real ][ x ≟ y ]
  equal {t = bit} x y = pred Term.[ bit ][ x ≟ y ]
  equal {t = bits n} x y = pred Term.[ bits n ][ x ≟ y ]
  equal {t = tuple _ []} x y = true
  equal {t = tuple _ (t ∷ ts)} x y = equal {t = t} (Term.func₁ proj₁ x) (Term.func₁ proj₁ y) ∧ equal (Term.func₁ proj₂ x) (Term.func₁ proj₂ y)
  equal {t = array t n} x y = all (some (Term.wknMeta (Term.wknMeta x) [ meta 1F ]↦ meta 0F ∧ Term.wknMeta (Term.wknMeta y) [ meta 1F ]↦ meta 0F))

open Construct public