Danila Fedorin
a82d54666a
- Spa.Showable: port of Showable.agda (quoted strings, map format) for output parity - Spa.Analysis.Utils: eval_combine₂ - Spa.Lattice.AboveBelow.le_cases: order of the flat lattice by cases - Spa.Analysis.Sign / Spa.Analysis.Constant: the four monotonicity POSTULATES from the Agda files are now proved theorems (via le_cases); interpretations, evaluator validity, analyze_correct per analysis - Main + lake exe spa: runs both analyses on the Agda test program; constant analysis folds unknown=0, sign analysis gives unknown=⊤ Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
412 lines
14 KiB
Lean4
412 lines
14 KiB
Lean4
/-
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Port of `Analysis/Sign.agda`.
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Correspondence:
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Sign (+ / - / 0ˢ) ↦ Sign.plus / Sign.minus / Sign.zero
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_≟ᵍ_, ≡-equiv, ≡-Decidable ↦ deriving DecidableEq
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SignLattice (AboveBelow) ↦ SignLattice
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AB.Plain 0ˢ ↦ signFixedHeight (AboveBelow.plainFixedHeight .zero)
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plus, minus ↦ plus, minus
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plus-Monoˡ/ʳ, minus-Monoˡ/ʳ (postulates in Agda!)
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↦ plus_mono_left/right, minus_mono_left/right —
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now actually proved, via AboveBelow.le_cases
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plus-Mono₂, minus-Mono₂ ↦ plus_mono₂, minus_mono₂
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⟦_⟧ᵍ ↦ interpSign
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⟦⟧ᵍ-respects-≈ᵍ ↦ (trivial with `=`)
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⟦⟧ᵍ-⊔ᵍ-∨, ⟦⟧ᵍ-⊓ᵍ-∧ ↦ interpSign_sup, interpSign_inf
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s₁≢s₂⇒¬s₁∧s₂ ↦ interpSign_mk_disjoint
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latticeInterpretationᵍ ↦ signInterpretation
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WithProg.eval, eval-Monoʳ ↦ SignAnalysis.eval, eval_mono
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SignEval (instance) ↦ SignAnalysis.exprEvaluator
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plus-valid, minus-valid ↦ plus_valid, minus_valid
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eval-valid, SignEvalValid ↦ eval_valid
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output ↦ SignAnalysis.output
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analyze-correct ↦ SignAnalysis.analyze_correct
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-/
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import Spa.Analysis.Forward
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import Spa.Analysis.Utils
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import Spa.Showable
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namespace Spa
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inductive Sign where
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| plus
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| minus
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| zero
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deriving DecidableEq
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instance : Showable Sign :=
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⟨fun
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| .plus => "+"
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| .minus => "-"
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| .zero => "0"⟩
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/-- Agda: the module parameter `x = 0ˢ` of `AB.Plain`. -/
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instance : Inhabited Sign := ⟨.zero⟩
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abbrev SignLattice : Type := AboveBelow Sign
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/-- Agda: `AB.Plain 0ˢ`'s `fixedHeight`. -/
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def signFixedHeight : FixedHeight SignLattice 2 :=
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AboveBelow.plainFixedHeight Sign.zero
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open AboveBelow in
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/-- Agda: `plus`. -/
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def plus : SignLattice → SignLattice → SignLattice
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| bot, _ => bot
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| _, bot => bot
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| top, _ => top
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| _, top => top
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| mk .plus, mk .plus => mk .plus
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| mk .plus, mk .minus => top
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| mk .plus, mk .zero => mk .plus
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| mk .minus, mk .plus => top
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| mk .minus, mk .minus => mk .minus
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| mk .minus, mk .zero => mk .minus
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| mk .zero, mk .plus => mk .plus
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| mk .zero, mk .minus => mk .minus
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| mk .zero, mk .zero => mk .zero
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open AboveBelow in
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/-- Agda: `minus`. -/
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def minus : SignLattice → SignLattice → SignLattice
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| bot, _ => bot
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| _, bot => bot
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| top, _ => top
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| _, top => top
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| mk .plus, mk .plus => top
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| mk .plus, mk .minus => mk .plus
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| mk .plus, mk .zero => mk .plus
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| mk .minus, mk .plus => mk .minus
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| mk .minus, mk .minus => top
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| mk .minus, mk .zero => mk .minus
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| mk .zero, mk .plus => mk .minus
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| mk .zero, mk .minus => mk .plus
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| mk .zero, mk .zero => mk .zero
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/-- Agda: `plus-Monoˡ` — a postulate there, a theorem here. -/
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theorem plus_mono_left (s₂ : SignLattice) : Monotone (plus · s₂) := by
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intro a b h
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rcases AboveBelow.le_cases h with rfl | rfl | rfl
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· rcases s₂ with _ | _ | y <;> rcases b with _ | _ | x <;>
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simp only [plus] <;>
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first
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| exact le_refl _
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| exact AboveBelow.le_top' _
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| exact AboveBelow.bot_le' _
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· rcases s₂ with _ | _ | y <;> rcases a with _ | _ | x <;>
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simp only [plus] <;>
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first
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| exact le_refl _
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| exact AboveBelow.le_top' _
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· exact le_refl _
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/-- Agda: `plus-Monoʳ` — a postulate there, a theorem here. -/
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theorem plus_mono_right (s₁ : SignLattice) : Monotone (plus s₁) := by
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intro a b h
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rcases AboveBelow.le_cases h with rfl | rfl | rfl
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· rcases s₁ with _ | _ | x <;> rcases b with _ | _ | y <;>
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simp only [plus] <;>
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first
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| exact le_refl _
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| exact AboveBelow.le_top' _
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| exact AboveBelow.bot_le' _
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· rcases s₁ with _ | _ | x <;> rcases a with _ | _ | y <;>
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simp only [plus] <;>
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first
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| exact le_refl _
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| exact AboveBelow.le_top' _
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· exact le_refl _
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/-- Agda: `plus-Mono₂`. -/
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theorem plus_mono₂ : Monotone₂ plus :=
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⟨plus_mono_left, plus_mono_right⟩
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/-- Agda: `minus-Monoˡ` — a postulate there, a theorem here. -/
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theorem minus_mono_left (s₂ : SignLattice) : Monotone (minus · s₂) := by
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intro a b h
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rcases AboveBelow.le_cases h with rfl | rfl | rfl
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· rcases s₂ with _ | _ | y <;> rcases b with _ | _ | x <;>
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simp only [minus] <;>
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first
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| exact le_refl _
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| exact AboveBelow.le_top' _
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| exact AboveBelow.bot_le' _
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· rcases s₂ with _ | _ | y <;> rcases a with _ | _ | x <;>
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simp only [minus] <;>
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first
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| exact le_refl _
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| exact AboveBelow.le_top' _
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· exact le_refl _
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/-- Agda: `minus-Monoʳ` — a postulate there, a theorem here. -/
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theorem minus_mono_right (s₁ : SignLattice) : Monotone (minus s₁) := by
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intro a b h
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rcases AboveBelow.le_cases h with rfl | rfl | rfl
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· rcases s₁ with _ | _ | x <;> rcases b with _ | _ | y <;>
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simp only [minus] <;>
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first
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| exact le_refl _
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| exact AboveBelow.le_top' _
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| exact AboveBelow.bot_le' _
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· rcases s₁ with _ | _ | x <;> rcases a with _ | _ | y <;>
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simp only [minus] <;>
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first
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| exact le_refl _
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| exact AboveBelow.le_top' _
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· exact le_refl _
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/-- Agda: `minus-Mono₂`. -/
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theorem minus_mono₂ : Monotone₂ minus :=
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⟨minus_mono_left, minus_mono_right⟩
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/-- Agda: `⟦_⟧ᵍ`. -/
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def interpSign : SignLattice → Value → Prop
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| .bot, _ => False
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| .top, _ => True
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| .mk .plus, v => ∃ n : ℕ, v = .int (n + 1)
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| .mk .zero, v => v = .int 0
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| .mk .minus, v => ∃ n : ℕ, v = .int (-(n + 1))
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/-- Agda: `s₁≢s₂⇒¬s₁∧s₂`. -/
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theorem interpSign_mk_disjoint {s₁ s₂ : Sign} (hne : s₁ ≠ s₂) {v : Value} :
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¬(interpSign (.mk s₁) v ∧ interpSign (.mk s₂) v) := by
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rintro ⟨h₁, h₂⟩
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rcases s₁ <;> rcases s₂ <;> try exact hne rfl
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all_goals simp only [interpSign] at h₁ h₂
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· obtain ⟨n₁, rfl⟩ := h₁
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obtain ⟨n₂, hv⟩ := h₂
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injection hv with hz
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omega
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· obtain ⟨n₁, rfl⟩ := h₁
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injection h₂ with hz
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omega
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· obtain ⟨n₁, rfl⟩ := h₁
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obtain ⟨n₂, hv⟩ := h₂
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injection hv with hz
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omega
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· obtain ⟨n₁, rfl⟩ := h₁
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injection h₂ with hz
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omega
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· subst h₁
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obtain ⟨n₂, hv⟩ := h₂
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injection hv with hz
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omega
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· subst h₁
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obtain ⟨n₂, hv⟩ := h₂
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injection hv with hz
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omega
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/-- Agda: `⟦⟧ᵍ-⊔ᵍ-∨`. -/
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theorem interpSign_sup {s₁ s₂ : SignLattice} (v : Value)
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(h : interpSign s₁ v ∨ interpSign s₂ v) : interpSign (s₁ ⊔ s₂) v := by
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rcases s₁ with _ | _ | x
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· rcases h with h | h
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· exact h.elim
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· rw [AboveBelow.bot_sup]
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exact h
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· exact trivial
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· rcases s₂ with _ | _ | y
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· rcases h with h | h
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· rw [AboveBelow.sup_bot]
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exact h
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· exact h.elim
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· rw [AboveBelow.sup_top]
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exact trivial
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· by_cases hxy : x = y
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· subst hxy
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rw [AboveBelow.mk_sup_mk, if_pos rfl]
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rcases h with h | h <;> exact h
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· rw [AboveBelow.mk_sup_mk, if_neg hxy]
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exact trivial
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/-- Agda: `⟦⟧ᵍ-⊓ᵍ-∧`. -/
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theorem interpSign_inf {s₁ s₂ : SignLattice} (v : Value)
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(h : interpSign s₁ v ∧ interpSign s₂ v) : interpSign (s₁ ⊓ s₂) v := by
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rcases s₁ with _ | _ | x
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· exact h.1
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· rw [AboveBelow.top_inf]
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exact h.2
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· rcases s₂ with _ | _ | y
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· exact h.2
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· rw [AboveBelow.inf_top]
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exact h.1
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· by_cases hxy : x = y
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· subst hxy
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rw [AboveBelow.mk_inf_mk, if_pos rfl]
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exact h.1
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· exact absurd h (interpSign_mk_disjoint hxy)
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/-- Agda: `latticeInterpretationᵍ`. -/
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def signInterpretation : LatticeInterpretation SignLattice where
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interp := interpSign
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interp_sup := fun {l₁ l₂} v h => interpSign_sup (s₁ := l₁) (s₂ := l₂) v h
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interp_inf := fun {l₁ l₂} v h => interpSign_inf (s₁ := l₁) (s₂ := l₂) v h
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namespace SignAnalysis
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/-! Agda: `module WithProg (prog : Program)`. -/
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variable (prog : Program)
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/-- Agda: `WithProg.eval`. -/
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def eval : Expr → VariableValues SignLattice prog → SignLattice
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| .add e₁ e₂, vs => plus (eval e₁ vs) (eval e₂ vs)
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| .sub e₁ e₂, vs => minus (eval e₁ vs) (eval e₂ vs)
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| .var k, vs =>
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if h : FiniteMap.MemKey k vs then (FiniteMap.locate h).1 else .top
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| .num 0, _ => .mk .zero
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| .num (_ + 1), _ => .mk .plus
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/-- Agda: `WithProg.eval-Monoʳ`. -/
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theorem eval_mono (e : Expr) : Monotone (eval prog e) := by
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induction e with
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| add e₁ e₂ ih₁ ih₂ =>
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intro vs₁ vs₂ h
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exact eval_combine₂ plus_mono₂ (ih₁ h) (ih₂ h)
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| sub e₁ e₂ ih₁ ih₂ =>
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intro vs₁ vs₂ h
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exact eval_combine₂ minus_mono₂ (ih₁ h) (ih₂ h)
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| var k =>
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intro vs₁ vs₂ h
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simp only [eval]
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by_cases hk : k ∈ prog.vars
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· rw [dif_pos (FiniteMap.memKey_iff.mpr hk),
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dif_pos (FiniteMap.memKey_iff.mpr hk)]
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exact FiniteMap.le_of_mem_mem prog.vars_nodup h
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(FiniteMap.locate _).2 (FiniteMap.locate _).2
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· rw [dif_neg (fun hm => hk (FiniteMap.memKey_iff.mp hm)),
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dif_neg (fun hm => hk (FiniteMap.memKey_iff.mp hm))]
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| num n =>
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intro vs₁ vs₂ _
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cases n <;> exact le_refl _
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/-- Agda: the `SignEval` instance. -/
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def exprEvaluator : ExprEvaluator SignLattice prog :=
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⟨eval prog, eval_mono prog⟩
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/-- Agda: `WithProg.result`/`output` — the analysis result, printed. -/
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def output : String :=
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show' (result signFixedHeight (exprEvaluator prog).toStmtEvaluator)
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/-- Agda: `plus-valid`. -/
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theorem plus_valid {g₁ g₂ : SignLattice} {z₁ z₂ : ℤ}
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(h₁ : interpSign g₁ (.int z₁)) (h₂ : interpSign g₂ (.int z₂)) :
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interpSign (plus g₁ g₂) (.int (z₁ + z₂)) := by
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rcases g₁ with _ | _ | s₁
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· exact h₁.elim
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· rcases g₂ with _ | _ | s₂
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· exact h₂.elim
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· exact trivial
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· exact trivial
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· rcases g₂ with _ | _ | s₂
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· exact h₂.elim
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· rcases s₁ <;> exact trivial
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· rcases s₁ <;> rcases s₂ <;>
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simp only [plus, interpSign, Value.int.injEq] at h₁ h₂ ⊢ <;>
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try trivial
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· obtain ⟨n₁, rfl⟩ := h₁
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obtain ⟨n₂, rfl⟩ := h₂
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exact ⟨n₁ + n₂ + 1, by omega⟩
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· obtain ⟨n₁, rfl⟩ := h₁
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subst h₂
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exact ⟨n₁, by omega⟩
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· obtain ⟨n₁, rfl⟩ := h₁
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obtain ⟨n₂, rfl⟩ := h₂
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exact ⟨n₁ + n₂ + 1, by omega⟩
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· obtain ⟨n₁, rfl⟩ := h₁
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subst h₂
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exact ⟨n₁, by omega⟩
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· subst h₁
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obtain ⟨n₂, rfl⟩ := h₂
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exact ⟨n₂, by omega⟩
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· subst h₁
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obtain ⟨n₂, rfl⟩ := h₂
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exact ⟨n₂, by omega⟩
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· subst h₁
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subst h₂
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omega
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/-- Agda: `minus-valid`. -/
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theorem minus_valid {g₁ g₂ : SignLattice} {z₁ z₂ : ℤ}
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(h₁ : interpSign g₁ (.int z₁)) (h₂ : interpSign g₂ (.int z₂)) :
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interpSign (minus g₁ g₂) (.int (z₁ - z₂)) := by
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rcases g₁ with _ | _ | s₁
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· exact h₁.elim
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· rcases g₂ with _ | _ | s₂
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· exact h₂.elim
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· exact trivial
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· exact trivial
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· rcases g₂ with _ | _ | s₂
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· exact h₂.elim
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· rcases s₁ <;> exact trivial
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· rcases s₁ <;> rcases s₂ <;>
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simp only [minus, interpSign, Value.int.injEq] at h₁ h₂ ⊢ <;>
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try trivial
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· obtain ⟨n₁, rfl⟩ := h₁
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obtain ⟨n₂, rfl⟩ := h₂
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exact ⟨n₁ + n₂ + 1, by omega⟩
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· obtain ⟨n₁, rfl⟩ := h₁
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subst h₂
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exact ⟨n₁, by omega⟩
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· obtain ⟨n₁, rfl⟩ := h₁
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obtain ⟨n₂, rfl⟩ := h₂
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exact ⟨n₁ + n₂ + 1, by omega⟩
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· obtain ⟨n₁, rfl⟩ := h₁
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subst h₂
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exact ⟨n₁, by omega⟩
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· subst h₁
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obtain ⟨n₂, rfl⟩ := h₂
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exact ⟨n₂, by omega⟩
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· subst h₁
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obtain ⟨n₂, rfl⟩ := h₂
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exact ⟨n₂, by omega⟩
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· subst h₁
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subst h₂
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omega
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/-- Agda: `eval-valid` / `SignEvalValid`. -/
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theorem eval_valid :
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IsValidExprEvaluator (exprEvaluator prog) signInterpretation := by
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intro vs ρ e v hev
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induction hev with
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| num n =>
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intro _
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show interpSign (eval prog (.num n) vs) (.int n)
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cases n with
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| zero => rfl
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| succ n' => exact ⟨n', congrArg Value.int (by push_cast; ring)⟩
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| var x v hxv =>
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intro hvs
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show interpSign (eval prog (.var x) vs) v
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simp only [eval]
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by_cases hk : FiniteMap.MemKey x vs
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· rw [dif_pos hk]
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exact hvs _ _ (FiniteMap.locate hk).2 _ hxv
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· rw [dif_neg hk]
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exact trivial
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| add e₁ e₂ z₁ z₂ _ _ ih₁ ih₂ =>
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intro hvs
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have h₁ : interpSign (eval prog e₁ vs) (.int z₁) := ih₁ hvs
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have h₂ : interpSign (eval prog e₂ vs) (.int z₂) := ih₂ hvs
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show interpSign (eval prog (.add e₁ e₂) vs) (.int (z₁ + z₂))
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exact plus_valid h₁ h₂
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| sub e₁ e₂ z₁ z₂ _ _ ih₁ ih₂ =>
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intro hvs
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have h₁ : interpSign (eval prog e₁ vs) (.int z₁) := ih₁ hvs
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have h₂ : interpSign (eval prog e₂ vs) (.int z₂) := ih₂ hvs
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show interpSign (eval prog (.sub e₁ e₂) vs) (.int (z₁ - z₂))
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exact minus_valid h₁ h₂
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/-- Agda: `WithProg.analyze-correct`. -/
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theorem analyze_correct {ρ : Env} (hrun : EvalStmt [] prog.rootStmt ρ) :
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interpV signInterpretation
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||
(variablesAt prog.finalState
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(result signFixedHeight (exprEvaluator prog).toStmtEvaluator)) ρ :=
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Spa.analyze_correct signFixedHeight
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||
((exprEvaluator prog).toStmtEvaluator_valid (eval_valid prog)) hrun
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||
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end SignAnalysis
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||
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end Spa
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