Don't Label Twice: Game, Set, Match
ProvedGameSetMatch.game_set_matchThe four-part statement of this mission, as one theorem. You win each point independently with probability .
(a) For odd : your probability of winning a best-of- is strictly greater than that of winning a best-of- of best-of-'s.
(b) For odd () and any : your probability of winning a best-of- is strictly greater than that of winning a best-of- of sets which are best-of-'s of games, …, which are best-of-'s of points. Since may be even, a tie in either format is decided by an independent fair coin.
(c) Under the setup of (b), each completed set is independently scored: with probability the winner gains one point in the match score, with probability the set is ignored, with probability the loser gains one point; , , . The rule is applied once per completed set, at the outermost layer only — games and points inside a set are plain majorities. In the best-of- each point counts as a set and receives the same random scoring. A tie is decided by a fair coin. Your winning probability is strictly greater for the best-of-.
(d) As (c), but you win only when your match score is strictly greater than your opponent's. If , your winning probability is strictly greater for the best-of-.
Conventions: "greater than " is and each odd; the list of set sizes is nonempty.
import Definitions.Def_GameSetMatchInternal
namespace GameSetMatch
/-- **Goal.** Don't Label Twice: Game, Set, Match — parts (a)–(d). -/
theorem game_set_match :
(∀ (q : ℝ) (m n : ℕ), 1 / 2 < q → q < 1 → Odd m → 1 < m → Odd n → 1 < n →
bestOfWinProb n (bestOfWinProb m q) < bestOfWinProb (n * m) q) ∧
(∀ (q : ℝ) (ms : List ℕ) (n : ℕ), 1 / 2 < q → q < 1 →
(∀ m ∈ ms, Odd m ∧ 1 < m) → ms ≠ [] → 1 < n →
bestOfFairCoinWinProb n (nestedBestOfWinProb ms q)
< bestOfFairCoinWinProb (n * ms.prod) q) ∧
(∀ (a b c q : ℝ) (ms : List ℕ) (n : ℕ), 0 ≤ a → 0 ≤ b → 0 ≤ c → a + b + c = 1 → c < a →
1 / 2 < q → q < 1 → (∀ m ∈ ms, Odd m ∧ 1 < m) → ms ≠ [] → 1 < n →
fairCoinWinProb (scoredSetLaw a b c (nestedBestOfWinProb ms q)) n
< fairCoinWinProb (scoredSetLaw a b c q) (n * ms.prod)) ∧
(∀ (a b c q : ℝ) (ms : List ℕ) (n : ℕ), 0 ≤ a → 1 / 2 ≤ b → 0 ≤ c → a + b + c = 1 → c < a →
1 / 2 < q → q < 1 → (∀ m ∈ ms, Odd m ∧ 1 < m) → ms ≠ [] → 1 < n →
strictWinProb (scoredSetLaw a b c (nestedBestOfWinProb ms q)) n
< strictWinProb (scoredSetLaw a b c q) (n * ms.prod)) := by
sorry
end GameSetMatchRead-back
What the Lean code literally says, in plain math · claude-opus-5
Blind read-back by an independent auditor agent (Opus 5) given only the Lean code and the platform auditor instructions; docstrings and comments ignored; identifier names treated as opaque; no access to the informal statement, the source proof, or the captain's intent.
This file states a single theorem whose statement is a conjunction of four universally
quantified implications, joined by "and" (all four must hold). The four conjuncts are read back
separately below, followed by an explicit comparison of their hypotheses. The proof is sorry.
Conjunct 1
For every real number q and all natural numbers m and n, if
1/2 < q(strict),q < 1(strict),mis odd,1 < m(strict, som ≥ 3given oddness),nis odd,1 < n(strict, son ≥ 3given oddness),
then
B_n( B_m(q) ) < B_{n·m}(q)
i.e. the strict-majority binomial tail of n trials whose success parameter is itself the
strict-majority tail of m trials at parameter q is strictly less than the strict-majority
tail of n·m trials at parameter q. Spelled out with the definition unfolded, the claim is
Σ_{j ≤ n, 2j > n} C(n, j) · X^j · (1 − X)^(n − j)
< Σ_{k ≤ nm, 2k > nm} C(nm, k) · q^k · (1 − q)^(nm − k)
where X = Σ_{i ≤ m, 2i > m} C(m, i) · q^i · (1 − q)^(m − i). The hypotheses are satisfiable
(e.g. q = 0.6, m = n = 3), so the conjunct is not vacuous.
Conjunct 2
For every real q, every list ms of natural numbers, and every natural n, if
1/2 < q,q < 1,- every entry
mof the listmssatisfies both "mis odd" and1 < m, msis not the empty list,1 < n(son ≥ 2;nis not required to be odd here),
then
F_n( Nest(ms, q) ) < F_{n · ∏ms}(q)
where F_N(x) = B_N(x) + T_N(x)/2 adds half of the "exact tie" term to the strict-majority tail,
Nest(ms, q) is the iterated composition B_{m₁}(B_{m₂}(…B_{m_k}(q)…)) with the head of ms
outermost, and ∏ms = m₁·m₂·⋯·m_k. Because ms is nonempty and each entry is odd and at least
3, ∏ms is odd and at least 3, so T_{∏ms} would be 0 — but note the tie term on the right is
T_{n·∏ms}, and n·∏ms is even whenever n is even, in which case that term is nonzero. On the
left the tie term is T_n, nonzero exactly when n is even. The inequality is strict and points
left-to-right (nested value strictly smaller). Hypotheses are satisfiable (e.g. q = 0.6,
ms = [3], n = 2).
Conjunct 3
For all real numbers a, b, c, q, every list ms of natural numbers, and every natural n, if
0 ≤ a,0 ≤ b,0 ≤ c,a + b + c = 1,c < a(strict),1/2 < q,q < 1,- every entry
mofmsis odd and satisfies1 < m, ms ≠ [],1 < n(nnot required odd),
then
W( ν[a,b,c; Nest(ms, q)] , n ) < W( ν[a,b,c; q] , n · ∏ms )
Unfolded: on the left, put r = Nest(ms, q) and form the three-point weight function on ℤ that
assigns r·a + (1−r)·c to +1, r·c + (1−r)·a to −1, b to 0, and 0 elsewhere; convolve it
with itself n times starting from the point mass at 0 (that is, form L^ν_n by the recursion of
definition (i)); then take the sum of L^ν_n(z) over integers 1 ≤ z ≤ n plus one half of
L^ν_n(0). On the right, do exactly the same with r replaced by the bare q and with n
replaced by n · ∏ms (so the outer sum runs over 1 ≤ z ≤ n·∏ms and the tie term is
L^ν_{n·∏ms}(0)/2). The claim is that the left quantity is strictly less than the right one.
Note that the number of convolution steps differs between the two sides (n versus n·∏ms), as
does the parameter fed into ν (Nest(ms, q) versus q), while a, b, c are the same on both
sides. Note also that no hypothesis directly constrains Nest(ms, q) to lie in [0, 1]; only
1/2 < q < 1 and the list conditions are assumed. The hypotheses 0 ≤ a, 0 ≤ c, c < a and
a + b + c = 1 force 0 ≤ c < a ≤ 1 and 0 ≤ b < 1; they are satisfiable (e.g.
a = 0.5, b = 0.3, c = 0.2), so the conjunct is not vacuous.
Conjunct 4
Same shape as conjunct 3 with two changes. For all reals a, b, c, q, every list ms of
naturals, and every natural n, if
0 ≤ a,1/2 ≤ b(non-strict),0 ≤ c,a + b + c = 1,c < a,1/2 < q,q < 1,- every entry of
msis odd and greater than 1, ms ≠ [],1 < n,
then
S( ν[a,b,c; Nest(ms, q)] , n ) < S( ν[a,b,c; q] , n · ∏ms )
i.e. the same construction as conjunct 3 but with the tie term dropped on both sides: the
left side is Σ_{z=1}^{n} L^ν_n(z) for ν = ν[a,b,c; Nest(ms,q)] and the right side is
Σ_{z=1}^{n·∏ms} L^ν_{n·∏ms}(z) for ν = ν[a,b,c; q]. Strict inequality, left less than right.
The hypotheses 1/2 ≤ b, 0 ≤ a, 0 ≤ c, a + b + c = 1 force a + c ≤ 1/2, hence
0 ≤ c < a ≤ 1/2; they are satisfiable (e.g. a = 0.3, b = 0.6, c = 0.1), so this conjunct is
not vacuous either.
How the four conjuncts' hypotheses differ
- Conjunct 1 vs conjunct 2. Conjunct 1 quantifies over a single natural
mand requiresmodd,m > 1, and additionallynodd,n > 1. Conjunct 2 replaces the singlemby a listms, requires each entry odd and greater than 1 plusms ≠ [], and drops the oddness requirement onn, keeping onlyn > 1. Correspondingly the conclusion of conjunct 1 usesB(strict majority only) on both sides, whereas conjunct 2 usesF = B + T/2(strict majority plus half the exact-tie term) on both sides. Conjunct 1's conclusion comparesB_n(B_m(q))withB_{n·m}(q); conjunct 2's comparesF_n(Nest(ms,q))withF_{n·∏ms}(q). - Conjunct 2 vs conjunct 3. Conjunct 3 keeps every hypothesis of conjunct 2 verbatim
(
1/2 < q,q < 1, all entries ofmsodd and> 1,ms ≠ [],1 < n) and adds three new real parametersa, b, ctogether with five new hypotheses:0 ≤ a,0 ≤ b,0 ≤ c,a + b + c = 1, andc < a. The conclusion changes from the binomial quantitiesFto the convolution quantitiesWbuilt fromν[a,b,c; ·]. - Conjunct 3 vs conjunct 4. The variable lists and every other hypothesis are identical. The
only hypothesis difference is that conjunct 3's
0 ≤ bis replaced in conjunct 4 by the strictly stronger1/2 ≤ b. The conclusion differs by dropping the half-tie term: conjunct 3 comparesW = S + Tie/2, conjunct 4 comparesSalone. So conjunct 4 has a stronger hypothesis and a different (not weaker or stronger by inspection) conclusion; neither conjunct implies the other by inspection. - Across all four.
1/2 < qandq < 1appear in all four.1 < nappears in all four. Oddness ofnappears only in conjunct 1. The list hypotheses (ms ≠ []and entrywise odd,> 1) appear in conjuncts 2, 3, 4. The parametersa, b, cand their constraints appear only in conjuncts 3 and 4. In every conjunct the final inequality is strict and oriented with the "nested / smaller index" expression on the left (the smaller side).
Confirmed by the mission captain (proposal self-audit).