| import Mathlib |
| import OAI.Combinatorics.IndependentSets.Encoding.Target |
|
|
| namespace OAI |
|
|
| namespace IndependentSetsGames.Foundations.Complexity |
|
|
| open Target |
|
|
| def parseLiteral («variables» : Nat) : List Nat → Option (Literal «variables» × List Nat) |
| | index :: sign :: rest => |
| if bounded : index < «variables» then |
| if sign = 0 then some (⟨⟨index, bounded⟩, false⟩, rest) |
| else if sign = 1 then some (⟨⟨index, bounded⟩, true⟩, rest) |
| else none |
| else none |
| | _ => none |
|
|
| @[simp] theorem parseLiteral_encoded {n : Nat} (literal : Literal n) (rest : List Nat) : |
| parseLiteral n (literalWords literal ++ rest) = some (literal, rest) := by |
| cases literal with |
| | mk index positive => |
| cases positive <;> simp [literalWords, parseLiteral, index.isLt] |
|
|
| def parseClause («variables» : Nat) (words : List Nat) : Option (Clause «variables» × List Nat) := do |
| let (a, words) ← parseLiteral «variables» words |
| let (b, words) ← parseLiteral «variables» words |
| let (c, words) ← parseLiteral «variables» words |
| return (⟨#[a, b, c], rfl⟩, words) |
|
|
| theorem clause_three_entries {n : Nat} (clause : Clause n) : |
| (⟨#[clause[0], clause[1], clause[2]], rfl⟩ : Clause n) = clause := by |
| apply Vector.ext |
| intro i hi |
| have cases_i : i = 0 ∨ i = 1 ∨ i = 2 := by omega |
| rcases cases_i with rfl | rfl | rfl <;> rfl |
|
|
| @[simp] theorem parseClause_encoded {n : Nat} (clause : Clause n) (rest : List Nat) : |
| parseClause n (clauseWords clause ++ rest) = some (clause, rest) := by |
| simp [clauseWords, List.append_assoc, parseClause, parseLiteral_encoded, |
| clause_three_entries] |
|
|
| def parseClauses («variables» : Nat) : Nat → List Nat → Option (List (Clause «variables») × List Nat) |
| | 0, words => some ([], words) |
| | count + 1, words => do |
| let (clause, words) ← parseClause «variables» words |
| let (clauses, words) ← parseClauses «variables» count words |
| return (clause :: clauses, words) |
|
|
| @[simp] theorem parseClauses_encoded {n : Nat} (clauses : List (Clause n)) (rest : List Nat) : |
| parseClauses n clauses.length (clauses.flatMap clauseWords ++ rest) = some (clauses, rest) := by |
| induction clauses with |
| | nil => rfl |
| | cons clause clauses ih => |
| simp [List.append_assoc, parseClauses, parseClause_encoded, ih] |
|
|
| def decodeFormulaWords : List Nat → Option Formula |
| | «variables» :: count :: words => do |
| let (clauses, trailing) ← parseClauses «variables» count words |
| if trailing = [] then some ⟨«variables», clauses⟩ else none |
| | _ => none |
|
|
| @[simp] theorem decodeFormulaWords_encoded (formula : Formula) : |
| decodeFormulaWords (formulaWords formula) = some formula := by |
| cases formula with |
| | mk «variables» clauses => |
| have parsed := parseClauses_encoded clauses [] |
| simp only [List.append_nil] at parsed |
| simp [decodeFormulaWords, formulaWords, parsed] |
|
|
| def decodeFormulaBits (bits : List Bool) : Option Formula := |
| decodeWords bits >>= decodeFormulaWords |
|
|
| @[simp] theorem decodeFormulaBits_encoded (formula : Formula) : |
| decodeFormulaBits (formulaBits formula) = some formula := by |
| simp [decodeFormulaBits, formulaBits] |
|
|
| theorem formulaBits_injective {first second : Formula} |
| (same : formulaBits first = formulaBits second) : first = second := by |
| have parsed := congrArg decodeFormulaBits same |
| simpa only [decodeFormulaBits_encoded, Option.some.injEq] using parsed |
|
|
| end IndependentSetsGames.Foundations.Complexity |
|
|
| end OAI |
|
|
