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Add lean source and binary files (part 61)
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import Mathlib
import OAI.Computability.MaxCut.Model
namespace OAI
namespace MaxCutGames.BinaryFormula
/-- An ordinary conjunction of three-slot clauses with sparse variable names.
Repeated names and repeated literals are permitted in every clause. -/
def clauseNames (clause : Clause) : List Nat :=
[clause[0].name, clause[1].name, clause[2].name]
end MaxCutGames.BinaryFormula
namespace MaxCutGames.BinaryEncoding
open BinaryFormula
@[simp] theorem bitsValue_bits (n : Nat) : bitsValue n.bits = n := by
induction n using Nat.binaryRec' with
| zero => simp [bitsValue]
| bit b n hn ih =>
rw [Nat.bits_append_bit n b hn]
simp only [bitsValue, ih]
/-- Prefix-free framing on the two-symbol input alphabet. -/
@[simp] theorem parseFrame_encoded (bits trailing : List Bool) :
parseFrame (frame bits ++ trailing) = some (bits, trailing) := by
induction bits with
| nil => rfl
| cons b bits ih => simp [frame, parseFrame, ih]
@[simp] theorem frame_length (bits : List Bool) :
(frame bits).length = 2 * bits.length + 1 := by
induction bits with
| nil => rfl
| cons b bits ih => simp [frame, ih]; omega
/-- Equality with the canonical digits rejects alternate padded encodings. -/
@[simp] theorem parseName_encoded (name : Nat) (rest : List Bool) :
parseName (nameBits name ++ rest) = some (name, rest) := by
simp [parseName, nameBits]
@[simp] theorem nameBits_length (name : Nat) :
(nameBits name).length = 2 * name.size + 1 := by
simp [nameBits, Nat.size_eq_bits_len]
theorem nameBits_length_le_of_lt_pow (name width : Nat) (bound : name < 2 ^ width) :
(nameBits name).length ≤ 2 * width + 1 := by
rw [nameBits_length]
have h := Nat.size_le.mpr bound
omega
def literalBits (literal : Literal) : List Bool :=
literal.positive :: nameBits literal.name
@[simp] theorem parseLiteral_encoded (literal : Literal) (rest : List Bool) :
parseLiteral (literalBits literal ++ rest) = some (literal, rest) := by
cases literal with
| mk name sign => simp [literalBits, parseLiteral]
@[simp] theorem literalBits_length (literal : Literal) :
(literalBits literal).length = 2 * literal.name.size + 2 := by
simp [literalBits]
def clauseBits (clause : Clause) : List Bool :=
literalBits clause[0] ++ literalBits clause[1] ++ literalBits clause[2]
theorem clause_three_entries (clause : Clause) : #v[clause[0], clause[1], clause[2]] = 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 (clause : Clause) (rest : List Bool) :
parseClause (clauseBits clause ++ rest) = some (clause, rest) := by
simp [clauseBits, List.append_assoc, parseClause, clause_three_entries]
def clauseNameSize (clause : Clause) : Nat :=
((clauseNames clause).map Nat.size).sum
@[simp] theorem clauseBits_length (clause : Clause) :
(clauseBits clause).length = 2 * clauseNameSize clause + 6 := by
simp [clauseBits, clauseNameSize, clauseNames]
omega
def clausesBits : List Clause → List Bool
| [] => [false]
| clause :: clauses => true :: (clauseBits clause ++ clausesBits clauses)
def formulaBits (formula : Formula) : List Bool := clausesBits formula.clauses
def namesBitSize (clauses : List Clause) : Nat :=
((clauses.flatMap clauseNames).map Nat.size).sum
@[simp] theorem namesBitSize_nil : namesBitSize [] = 0 := rfl
@[simp] theorem namesBitSize_cons (clause : Clause) (clauses : List Clause) :
namesBitSize (clause :: clauses) = clauseNameSize clause + namesBitSize clauses := by
simp [namesBitSize, clauseNameSize]
theorem clausesBits_length (clauses : List Clause) :
(clausesBits clauses).length = 7 * clauses.length + 2 * namesBitSize clauses + 1 := by
induction clauses with
| nil => rfl
| cons clause clauses ih =>
simp only [clausesBits, List.length_cons, List.length_append, clauseBits_length,
namesBitSize_cons, ih]
omega
theorem formulaBits_length (formula : Formula) :
(formulaBits formula).length =
7 * formula.clauses.length + 2 * namesBitSize formula.clauses + 1 :=
clausesBits_length formula.clauses
theorem clauses_length_lt_bits (clauses : List Clause) :
clauses.length < (clausesBits clauses).length := by
rw [clausesBits_length]
omega
/-- Binary digits, one sign per literal, and one terminal bit form a natural
reference size. The concrete framing adds only a fixed multiplicative factor. -/
def ordinarySize (formula : Formula) : Nat :=
3 * formula.clauses.length + namesBitSize formula.clauses + 1
theorem ordinarySize_le_bits (formula : Formula) :
ordinarySize formula ≤ (formulaBits formula).length := by
rw [formulaBits_length]
unfold ordinarySize
omega
theorem bits_le_three_ordinarySize (formula : Formula) :
(formulaBits formula).length ≤ 3 * ordinarySize formula := by
rw [formulaBits_length]
unfold ordinarySize
omega
/-- Fuel bounds the number of clause iterations, not the size of any name. -/
@[simp] theorem parseClauses_encoded (clauses : List Clause) (rest : List Bool)
(fuel : Nat) (enough : clauses.length < fuel) :
parseClauses fuel (clausesBits clauses ++ rest) = some (clauses, rest) := by
induction clauses generalizing fuel with
| nil =>
cases fuel with
| zero => omega
| succ fuel => simp [clausesBits, parseClauses]
| cons clause clauses ih =>
cases fuel with
| zero => omega
| succ fuel =>
have hrest : clauses.length < fuel := by simp only [List.length_cons] at enough; omega
simp [clausesBits, parseClauses, List.append_assoc, ih fuel hrest]
@[simp] theorem decodeFormula_encoded (formula : Formula) :
decodeFormula (formulaBits formula) = some formula := by
cases formula with
| mk clauses =>
have hlen := clauses_length_lt_bits clauses
have parsed := parseClauses_encoded clauses [] ((clausesBits clauses).length + 1) (by omega)
simp only [List.append_nil] at parsed
simp [formulaBits, decodeFormula, parsed]
/-- This preserves every literal and clause occurrence, including duplicates. -/
theorem formulaBits_injective {first second : Formula}
(same : formulaBits first = formulaBits second) : first = second := by
have parsed := congrArg decodeFormula same
simpa only [decodeFormula_encoded, Option.some.injEq] using parsed
end MaxCutGames.BinaryEncoding
/- The ordinary binary 3SAT language, including rejection of malformed words,
is exactly `MaxCutGames.BinaryLanguage.language`. -/
/- A finite simple unweighted graph with its full Boolean adjacency table.
Symmetry and the zero diagonal forbid directed edges, loops and repetitions.
No real/rational edge weights occur. -/
/- Each unordered distinct edge crossing the cut is counted exactly once. -/
/- An actual finite maximum, not a supremum over a relaxed cut domain. -/
/- A full binary output encoding: canonical delimited binary size, canonical
delimited binary Q, followed by the complete n-by-n Boolean adjacency table,
in lexicographic order. Thus neither Q nor adjacency is an oracle. -/
/- The target asserts a reduction, rather than a conditional implication from
an assumed reduction. -/
end OAI