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putnam_1977_a4
abbrev putnam_1977_a4_solution : RatFunc ℝ := sorry -- RatFunc.X / (1 - RatFunc.X) /-- Find $\sum_{n=0}^{\infty} \frac{x^{2^n}}{1 - x^{2^{n+1}}}$ as a rational function of $x$ for $x \in (0, 1)$. -/ theorem putnam_1977_a4 : βˆ€ x ∈ Ioo 0 1, putnam_1977_a4_solution.eval (id ℝ) x = βˆ‘' n : β„•, x ^ 2 ^ n / (1 - x ^ 2 ^ (n + 1)) := sorry
bdfc699256ecc967
putnam_2000_a1
abbrev putnam_2000_a1_solution : ℝ β†’ Set ℝ := sorry -- (fun A : ℝ => Set.Ioo 0 (A ^ 2)) /-- Let $A$ be a positive real number. What are the possible values of $\sum_{j=0}^\infty x_j^2$, given that $x_0,x_1,\ldots$ are positive numbers for which $\sum_{j=0}^\infty x_j=A$? -/ theorem putnam_2000_a1 (A : ℝ) (Apos : A > 0) : {S : ℝ | βˆƒ x : β„• β†’ ℝ, (βˆ€ j : β„•, x j > 0) ∧ (βˆ‘' j : β„•, x j) = A ∧ (βˆ‘' j : β„•, (x j) ^ 2) = S} = putnam_2000_a1_solution A := sorry
7ea2b76275b22c17
putnam_2010_a1
abbrev putnam_2010_a1_solution : β„• β†’ β„• := sorry -- (fun n : β„• => Nat.ceil ((n : ℝ) / 2)) /-- Given a positive integer $n$, what is the largest $k$ such that the numbers $1,2,\dots,n$ can be put into $k$ boxes so that the sum of the numbers in each box is the same? [When $n=8$, the example $\{1,2,3,6\},\{4,8\},\{5,7\}$ shows that the largest $k$ is \emph{at least} $3$.] -/ theorem putnam_2010_a1 (n : β„•) (kboxes : β„• β†’ Prop) (npos : n > 0) (hkboxes : βˆ€ k : β„•, kboxes k = (βˆƒ boxes : Finset.Icc 1 n β†’ Fin k, βˆ€ i j : Fin k, βˆ‘ x in Finset.univ.filter (boxes Β· = i), (x : β„•) = βˆ‘ x in Finset.univ.filter (boxes Β· = j), (x : β„•))) : IsGreatest kboxes (putnam_2010_a1_solution n) := sorry
487e03787f69ef74
putnam_1995_a1
theorem putnam_1995_a1 (S : Set ℝ) (hS : βˆ€ a ∈ S, βˆ€ b ∈ S, a * b ∈ S) (T U : Set ℝ) (hsub : T βŠ† S ∧ U βŠ† S) (hunion : T βˆͺ U = S) (hdisj : T ∩ U = βˆ…) (hT3 : βˆ€ a ∈ T, βˆ€ b ∈ T, βˆ€ c ∈ T, a * b * c ∈ T) (hU3 : βˆ€ a ∈ U, βˆ€ b ∈ U, βˆ€ c ∈ U, a * b * c ∈ U) : (βˆ€ a ∈ T, βˆ€ b ∈ T, a * b ∈ T) ∨ (βˆ€ a ∈ U, βˆ€ b ∈ U, a * b ∈ U) := sorry
9815d3d1b44e9620
putnam_1985_a1
abbrev putnam_1985_a1_solution : β„• Γ— β„• Γ— β„• Γ— β„• := sorry -- (10, 10, 0, 0) /-- Determine, with proof, the number of ordered triples $(A_1, A_2, A_3)$ of sets which have the property that \begin{enumerate} \item[(i)] $A_1 \cup A_2 \cup A_3 = \{1,2,3,4,5,6,7,8,9,10\}$, and \item[(ii)] $A_1 \cap A_2 \cap A_3 = \emptyset$. \end{enumerate} Express your answer in the form $2^a 3^b 5^c 7^d$, where $a,b,c,d$ are nonnegative integers. -/ theorem putnam_1985_a1 : let (a, b, c, d) := putnam_1985_a1_solution; {(A1, A2, A3) : Set β„€ Γ— Set β„€ Γ— Set β„€ | A1 βˆͺ A2 βˆͺ A3 = Icc 1 10 ∧ A1 ∩ A2 ∩ A3 = βˆ…}.ncard = 2 ^ a * 3 ^ b * 5 ^ c * 7 ^ d := sorry
eb93f1dfaf2655d6
putnam_1992_a5
theorem putnam_1992_a5 (a : β„• β†’ β„•) (ha : a = fun n ↦ ite (Even {i | (digits 2 n).get i = 1}.ncard) 0 1) : Β¬βˆƒ k > 0, βˆƒ m > 0, βˆ€ j ≀ m - 1, a (k + j) = a (k + m + j) ∧ a (k + m + j) = a (k + 2 * m + j) := sorry
2fb48dc873839c8d
putnam_1982_a5
theorem putnam_1982_a5 (a b c d : β„€) (hpos : a > 0 ∧ b > 0 ∧ c > 0 ∧ d > 0) (hac : a + c ≀ 1982) (hfrac : (a : ℝ) / b + (c : ℝ) / d < 1) : (1 - (a : ℝ) / b - (c : ℝ) / d > 1 / 1983 ^ 3) := sorry
cb8f331474bf0bfa
putnam_2018_b6
theorem putnam_2018_b6 (S : Finset (Fin 2018 β†’ β„€)) (hS : S = {s : Fin 2018 β†’ β„€ | (βˆ€ i : Fin 2018, s i ∈ ({1, 2, 3, 4, 5, 6, 10} : Set β„€)) ∧ (βˆ‘ i : Fin 2018, s i) = 3860}) : S.card ≀ 2 ^ 3860 * ((2018 : ℝ) / 2048) ^ 2018 := sorry
76242f65e0cf821a
putnam_2008_b6
theorem putnam_2008_b6 (n k : β„•) (hnk : n > 0 ∧ k > 0) : Odd (Set.ncard {s : Equiv.Perm (Fin n) | klimited k n s}) ↔ (n ≑ 0 [MOD 2*k+1] ∨ n ≑ 1 [MOD 2*k+1]) := sorry
6faf0f60f5485143
putnam_2007_a5
theorem putnam_2007_a5 (G : Type*) [Group G] [Fintype G] (p n : β„•) (hp : Nat.Prime p) (hn : n = {g : G | orderOf g = p}.encard) : n = 0 ∨ p ∣ (n + 1) := sorry
b1852b36feead356
putnam_1970_a1
theorem putnam_1970_a1 (a b : ℝ) (ha : a > 0) (hb : b > 0) (f : ℝ β†’ ℝ) (f_def : f = fun x : ℝ => Real.exp (a*x) * Real.cos (b*x)) (p : β„• β†’ ℝ) (hp : βˆƒ c : ℝ, c > 0 ∧ βˆ€ x ∈ ball 0 c, βˆ‘' n : β„•, (p n)*x^n = f x) (S : Set β„•) (S_def : S = {n : β„• | p n = 0}) : S = βˆ… ∨ Β¬Finite S := sorry
4860dce88963b435
putnam_2007_a4
abbrev putnam_2007_a4_solution : Set (Polynomial ℝ) := sorry -- {f : Polynomial ℝ | βˆƒ d : β„•, βˆƒ c β‰₯ (1 : β„€) - d, βˆ€ n : ℝ, f.eval n = (1 / 9) * ((10 ^ c) * (9 * n + 1) ^ d - 1)} /-- A \emph{repunit} is a positive integer whose digits in base 10 are all ones. Find all polynomials $f$ with real coefficients such that if $n$ is a repunit, then so is $f(n)$. -/ theorem putnam_2007_a4 (S : Set (Polynomial ℝ)) (repunit : ℝ β†’ Prop) (hrepunit : βˆ€ x, repunit x ↔ x > 0 ∧ x = floor x ∧ βˆ€ d ∈ (digits 10 (floor x)), d = 1) (hS : βˆ€ f, f ∈ S ↔ (βˆ€ n : ℝ, repunit n β†’ repunit (f.eval n))) : (S = putnam_2007_a4_solution) := sorry
b6a7b679b7fb5613
putnam_2017_a4
theorem putnam_2017_a4 (N : β„•) (score : Fin (2 * N) β†’ Fin 11) (hsurj : βˆ€ k : Fin 11, βˆƒ i : Fin (2 * N), score i = k) (havg : (βˆ‘ i : Fin (2 * N), (score i : ℝ)) / (2 * N) = 7.4) : (βˆƒ s : Finset (Fin (2 * N)), s.card = N ∧ (βˆ‘ i in s, (score i : ℝ)) / N = 7.4 ∧ (βˆ‘ i in sᢜ, (score i : ℝ)) / N = 7.4) := sorry
dbffa30c1b994a53
putnam_1992_a4
abbrev putnam_1992_a4_solution : β„• β†’ ℝ := sorry -- fun k ↦ ite (Even k) ((-1) ^ (k / 2) * factorial k) 0 /-- Let $f$ be an infinitely differentiable real-valued function defined on the real numbers. If \[ f\left( \frac{1}{n} \right) = \frac{n^2}{n^2 + 1}, \qquad n = 1, 2, 3, \dots, \] compute the values of the derivatives $f^{(k)}(0), k = 1, 2, 3, \dots$. -/ theorem putnam_1992_a4 (f : ℝ β†’ ℝ) (hfdiff : ContDiff ℝ ⊀ f) (hf : βˆ€ n : β„•, n > 0 β†’ f (1 / n) = n ^ 2 / (n ^ 2 + 1)) : (βˆ€ k : β„•, k > 0 β†’ iteratedDeriv k f 0 = putnam_1992_a4_solution k) := sorry
3729b5784bfbe17a
putnam_1982_a4
theorem putnam_1982_a4 (hdiffeq : (ℝ β†’ ℝ) β†’ (ℝ β†’ ℝ) β†’ Prop) (hdiffeq_def : βˆ€ y z, hdiffeq y z ↔ y 0 = 1 ∧ z 0 = 0 ∧ ContDiff ℝ 1 y ∧ ContDiff ℝ 1 z ∧ (βˆ€ x : ℝ, deriv y x = -1 * (z x)^3 ∧ deriv z x = (y x)^3)) (f g : ℝ β†’ ℝ) (hfgsat : hdiffeq f g) (hfgonly : Β¬(βˆƒ f' g' : ℝ β†’ ℝ, (f β‰  f' ∨ g β‰  g') ∧ hdiffeq f' g')) : βˆƒ L : ℝ, L > 0 ∧ Function.Periodic f L ∧ Function.Periodic g L := sorry
66deacfe34ae105d
putnam_1978_b6
theorem putnam_1978_b6 (a : β„• β†’ β„• β†’ ℝ) (ha : βˆ€ i j, a i j ∈ Icc 0 1) (m n : β„•) (mnpos : m > 0 ∧ n > 0) : ((βˆ‘ i in Finset.Icc 1 n, βˆ‘ j in Finset.Icc 1 (m * i), a i j / i) ^ 2 ≀ 2 * m * βˆ‘ i in Finset.Icc 1 n, βˆ‘ j in Finset.Icc 1 (m * i), a i j) := sorry
c872e9c2972df93f
putnam_1968_b6
theorem putnam_1968_b6 : Β¬βˆƒ K : β„• β†’ Set β„š, (βˆ€ n : β„•, IsCompact (K n)) ∧ (βˆ€ S : Set β„š, IsCompact S β†’ βˆƒ n : β„•, S βŠ† K n) := sorry
e17610b10277d891
putnam_1967_a5
theorem putnam_1967_a5 (R : Set (EuclideanSpace ℝ (Fin 2))) (hR : Convex ℝ R ∧ (MeasureTheory.volume R).toReal > Real.pi / 4) : βˆƒ P ∈ R, βˆƒ Q ∈ R, dist P Q = 1 := sorry
7ae2860077304c40
putnam_2022_b4
abbrev putnam_2022_b4_solution : Set β„• := sorry -- {n : β„• | 3 ∣ n ∧ n β‰₯ 9} /-- Find all integers $n$ with $n \geq 4$ for which there exists a sequence of distinct real numbers $x_1,\dots,x_n$ such that each of the sets $\{x_1,x_2,x_3\},\{x_2,x_3,x_4\},\dots,\{x_{n-2},x_{n-1},x_n\},\{x_{n-1},x_n,x_1\}$, and $\{x_n,x_1,x_2\}$ forms a $3$-term arithmetic progression when arranged in increasing order. -/ theorem putnam_2022_b4 (n : β„•) (hn : n β‰₯ 4) (ap3 : ℝ β†’ ℝ β†’ ℝ β†’ Prop) (xprog : (β„• β†’ ℝ) β†’ Prop) (hap3 : βˆ€ x0 x1 x2, ap3 x0 x1 x2 ↔ βˆ€ o0 o1 o2 : ℝ, (o0 < o1 ∧ o1 < o2 ∧ ({o0, o1, o2} : Set ℝ) = {x0, x1, x2}) β†’ (o1 - o0 = o2 - o1)) (hxprog : βˆ€ x, xprog x ↔ ((βˆ€ i j : Fin n, i.1 β‰  j.1 β†’ x i.1 β‰  x j.1) ∧ (βˆ€ i : Fin n, ap3 (x i.1) (x ((i.1 + 1) % n)) (x ((i.1 + 2) % n))))) : (βˆƒ x, xprog x) ↔ n ∈ putnam_2022_b4_solution := sorry
de91bdf662d58ef8
putnam_1977_a5
theorem putnam_1977_a5 (p m n : β„•) (hp : Nat.Prime p) (hmgen : m β‰₯ n) : (choose (p * m) (p * n) ≑ choose m n [MOD p]) := sorry
978cf504d604cc5a
putnam_1999_b5
abbrev putnam_1999_b5_solution : β„• β†’ ℝ := sorry -- fun n => 1 - n^2/4 /-- For an integer $n\geq 3$, let $\theta=2\pi/n$. Evaluate the determinant of the $n\times n$ matrix $I+A$, where $I$ is the $n\times n$ identity matrix and $A=(a_{jk})$ has entries $a_{jk}=\cos(j\theta+k\theta)$ for all $j,k$. -/ theorem putnam_1999_b5 (n : β„•) (hn : n β‰₯ 3) (theta : ℝ) (htheta : theta = 2 * Real.pi / n) (A : Matrix (Fin n) (Fin n) ℝ) (hA : A = fun j k => Real.cos ((j.1 + 1) * theta + (k.1 + 1) * theta)) : (1 + A).det = putnam_1999_b5_solution n := sorry
04a793fbf6f644e9
asserts
abbrev putnam_1974_a3_solution : (Set β„•) Γ— (Set β„•) := sorry -- ({p : β„• | p.Prime ∧ p ≑ 1 [MOD 8]}, {p : β„• | p.Prime ∧ p ≑ 5 [MOD 8]}) /-- A well-known theorem asserts that a prime $p > 2$ can be written as the sum of two perfect squres if and only if $p \equiv 1 \bmod 4$. Find which primes $p > 2$ can be written in each of the following forms, using (not necessarily positive) integers $x$ and $y$: (a) $x^2 + 16y^2$, (b) $4x^2 + 4xy + 5y^2$. -/ theorem putnam_1974_a3 (assmption : βˆ€ p : β„•, p.Prime ∧ p > 2 β†’ ((βˆƒ m n : β„€, p = m^2 + n^2) ↔ p ≑ 1 [MOD 4])) : βˆ€ p : β„•, ((p.Prime ∧ p > 2 ∧ (βˆƒ x y : β„€, p = x^2 + 16*y^2)) ↔ p ∈ putnam_1974_a3_solution.1) ∧ ((p.Prime ∧ p > 2 ∧ (βˆƒ x y : β„€, p = 4*x^2 + 4*x*y + 5*y^2)) ↔ p ∈ putnam_1974_a3_solution.2) := sorry
db78fe08287f5cff
putnam_2021_b2
abbrev putnam_2021_b2_solution : ℝ := sorry -- 2 / 3 /-- Determine the maximum value of the sum $S = \sum_{n=1}^\infty \frac{n}{2^n}(a_1a_2 \dots a_n)^{1/n}$ over all sequences $a_1,a_2,a_3,\dots$ of nonnegative real numbers satisfying $\sum_{k=1}^\infty a_k=1$. -/ theorem putnam_2021_b2 : IsGreatest {S | βˆƒ a : β„•+ β†’ ℝ, (βˆ‘' k, a k = 1) ∧ (βˆ€ k, 0 ≀ a k) ∧ S = βˆ‘' n : β„•+, n / 2 ^ (n : β„•) * (∏ k in Finset.Icc 1 n, a k) ^ (1 / n : ℝ)} putnam_2021_b2_solution := sorry
222bc354760bf00c
putnam_1964_a3
theorem putnam_1964_a3 (x a b : β„• β†’ ℝ) (hxdense : range x βŠ† Ioo 0 1 ∧ closure (range x) βŠ‡ Ioo 0 1) (hxinj : Injective x) (ha : a = fun n ↦ x n - sSup ({0} βˆͺ {p : ℝ | p < x n ∧ βˆƒ i < n, p = x i})) (hb : b = fun n ↦ sInf ({1} βˆͺ {p : ℝ | p > x n ∧ βˆƒ i < n, p = x i}) - x n) : (βˆ‘' n : β„•, a n * b n * (a n + b n) = 1 / 3) := sorry
59f3b015b84783b4
putnam_2013_a6
theorem putnam_2013_a6 (w : β„€ β†’ β„€ β†’ β„€) (A : Finset (β„€ Γ— β„€) β†’ β„€) (hwn1 : w (-2) (-2) = -1 ∧ w 2 (-2) = -1 ∧ w (-2) 2 = -1 ∧ w 2 2 = -1) (hwn2 : w (-1) (-2) = -2 ∧ w 1 (-2) = -2 ∧ w (-2) (-1) = -2 ∧ w 2 (-1) = -2 ∧ w (-2) 1 = -2 ∧ w 2 1 = -2 ∧ w (-1) 2 = -2 ∧ w 1 2 = -2) (hw2 : w 0 (-2) = 2 ∧ w (-2) 0 = 2 ∧ w 2 0 = 2 ∧ w 0 2 = 2) (hw4 : w (-1) (-1) = 4 ∧ w 1 (-1) = 4 ∧ w (-1) 1 = 4 ∧ w 1 1 = 4) (hwn4 : w 0 (-1) = -4 ∧ w (-1) 0 = -4 ∧ w 1 0 = -4 ∧ w 0 1 = -4) (hw12 : w 0 0 = 12) (hw0 : βˆ€ a b : β„€, (|a| > 2 ∨ |b| > 2) β†’ w a b = 0) (hA : βˆ€ S, A S = βˆ‘ s in S, βˆ‘ s' in S, w (s - s').1 (s - s').2) : βˆ€ S : Finset (β„€ Γ— β„€), Nonempty S β†’ A S > 0 := sorry
97ee3ec31151a83b
putnam_2003_a6
abbrev putnam_2003_a6_solution : Prop := sorry -- True /-- For a set $S$ of nonnegative integers, let $r_S(n)$ denote the number of ordered pairs $(s_1,s_2)$ such that $s_1 \in S$, $s_2 \in S$, $s_1 \ne s_2$, and $s_1+s_2=n$. Is it possible to partition the nonnegative integers into two sets $A$ and $B$ in such a way that $r_A(n)=r_B(n)$ for all $n$? -/ theorem putnam_2003_a6 (r : Set β„• β†’ β„• β†’ β„•) (hr : βˆ€ S n, r S n = βˆ‘' s1 : S, βˆ‘' s2 : S, if (s1 β‰  s2 ∧ s1 + s2 = n) then 1 else 0) : (βˆƒ A B : Set β„•, A βˆͺ B = β„• ∧ A ∩ B = βˆ… ∧ (βˆ€ n : β„•, r A n = r B n)) ↔ putnam_2003_a6_solution := sorry
1db2d9bacbe1fc95
putnam_1986_a6
abbrev putnam_1986_a6_solution : (β„• β†’ β„•) β†’ β„• β†’ ℝ := sorry -- fun b n ↦ (∏ i : Finset.Icc 1 n, b i) / Nat.factorial n /-- Let $a_1, a_2, \dots, a_n$ be real numbers, and let $b_1, b_2, \dots, b_n$ be distinct positive integers. Suppose that there is a polynomial $f(x)$ satisfying the identity \[ (1-x)^n f(x) = 1 + \sum_{i=1}^n a_i x^{b_i}. \] Find a simple expression (not involving any sums) for $f(1)$ in terms of $b_1, b_2, \dots, b_n$ and $n$ (but independent of $a_1, a_2, \dots, a_n$). -/ theorem putnam_1986_a6 (n : β„•) (npos : n > 0) (a : β„• β†’ ℝ) (b : β„• β†’ β„•) (bpos : βˆ€ i ∈ Finset.Icc 1 n, b i > 0) (binj : βˆ€ i ∈ Finset.Icc 1 n, βˆ€ j ∈ Finset.Icc 1 n, b i = b j β†’ i = j) (f : Polynomial ℝ) (hf : βˆ€ x : ℝ, (1 - x) ^ n * f.eval x = 1 + βˆ‘ i : Finset.Icc 1 n, (a i) * x ^ (b i)) : (f.eval 1 = putnam_1986_a6_solution b n) := sorry
6e635db1f8105862
putnam_1996_a6
abbrev putnam_1996_a6_solution : ℝ β†’ Set (ℝ β†’ ℝ) := sorry -- (fun c : ℝ => if c ≀ 1 / 4 then {f : ℝ β†’ ℝ | βˆƒ d : ℝ, βˆ€ x : ℝ, f x = d} else {f : ℝ β†’ ℝ | ContinuousOn f (Set.Icc 0 c) ∧ f 0 = f c ∧ (βˆ€ x > 0, f x = f (x ^ 2 + c)) ∧ (βˆ€ x < 0, f x = f (-x))}) /-- Let $c>0$ be a constant. Give a complete description, with proof, of the set of all continuous functions $f:\mathbb{R} \to \mathbb{R}$ such that $f(x)=f(x^2+c)$ for all $x \in \mathbb{R}$. -/ theorem putnam_1996_a6 (c : ℝ) (f : ℝ β†’ ℝ) (cgt0 : c > 0) : (Continuous f ∧ βˆ€ x : ℝ, f x = f (x ^ 2 + c)) ↔ f ∈ putnam_1996_a6_solution c := sorry
77309532097f1c06
putnam_1991_a2
abbrev putnam_1991_a2_solution : Prop := sorry -- False /-- Let $\mathbf{A}$ and $\mathbf{B}$ be different $n \times n$ matrices with real entries. If $\mathbf{A}^3=\mathbf{B}^3$ and $\mathbf{A}^2\mathbf{B}=\mathbf{B}^2\mathbf{A}$, can $\mathbf{A}^2+\mathbf{B}^2$ be invertible? -/ theorem putnam_1991_a2 (n : β„•) (hn : 1 ≀ n) : putnam_1991_a2_solution ↔ (βˆƒ A B : Matrix (Fin n) (Fin n) ℝ, A β‰  B ∧ A ^ 3 = B ^ 3 ∧ A ^ 2 * B = B ^ 2 * A ∧ Nonempty (Invertible (A ^ 2 + B ^ 2))) := sorry
1e9ff3559c5c5884
putnam_2014_a2
abbrev putnam_2014_a2_solution : β„• β†’ ℝ := sorry -- (fun n : β„• => (-1) ^ (n - 1) / ((n - 1)! * (n)!)) /-- Let $A$ be the $n \times n$ matrix whose entry in the $i$-th row and $j$-th column is $\frac{1}{\min(i,j)}$ for $1 \leq i,j \leq n$. Compute $\det(A)$. -/ theorem putnam_2014_a2 (n : β„•) (A : Matrix (Fin n) (Fin n) ℝ) (npos : n > 0) (hA : βˆ€ i j : Fin n, A i j = 1 / min (i.1 + 1 : β„š) (j.1 + 1)) : A.det = putnam_2014_a2_solution n := sorry
954747916dc3f701
putnam_1965_a2
theorem putnam_1965_a2 : βˆ€ n > 0, βˆ‘ r in Finset.Icc 0 ((n - 1)/2), ((n - 2*r) * Nat.choose n r / (n : β„š))^2 = (Nat.choose (2*n - 2) (n - 1))/(n : β„š) := sorry
f9f1f1e75a1487ef
putnam_1988_b4
theorem putnam_1988_b4 (a : β„• β†’ ℝ) (IsPosConv : (β„• β†’ ℝ) β†’ Prop) (IsPosConv_def : βˆ€ a' : β„• β†’ ℝ, IsPosConv a' ↔ (βˆ€ n β‰₯ 1, a' n > 0) ∧ (βˆƒ s : ℝ, Tendsto (fun N : β„• => βˆ‘ n : Set.Icc 1 N, a' n) atTop (𝓝 s))) : (IsPosConv a) β†’ IsPosConv (fun n : β„• => (a n) ^ ((n : ℝ) / (n + 1))) := sorry
f3c0f493f646df6e
putnam_1975_a2
abbrev putnam_1975_a2_solution : (ℝ Γ— ℝ) β†’ Prop := sorry -- fun (b, c) => c < 1 ∧ c - b > -1 ∧ c + b > -1 /-- For which ordered pairs $(b, c)$ of real numbers do both roots of $z^2 + bz + c$ lie strictly inside the unit disk (i.e., $\{|z| < 1\}$) in the complex plane? -/ theorem putnam_1975_a2 : βˆ€ b c : ℝ, (βˆ€ z : β„‚, (X^2 + (C (b : β„‚))*X + (C (c : β„‚)) : Polynomial β„‚).eval z = 0 β†’ β€–zβ€– < 1) ↔ putnam_1975_a2_solution (b, c) := sorry
5511d29ccc594e36
putnam_1998_b4
abbrev putnam_1998_b4_solution : Set (β„• Γ— β„•) := sorry -- {nm | let ⟨n,m⟩ := nm; multiplicity 2 n β‰  multiplicity 2 m} /-- Find necessary and sufficient conditions on positive integers $m$ and $n$ so that \[\sum_{i=0}^{mn-1} (-1)^{\lfloor i/m \rfloor +\lfloor i/n\rfloor}=0.\] -/ theorem putnam_1998_b4 (quantity : β„• β†’ β„• β†’ β„€) (hquantity : quantity = fun n m => βˆ‘ i in Finset.range (m * n), (-1)^(i/m + i/n)) (n m : β„•) (hnm : n > 0 ∧ m > 0) : quantity n m = 0 ↔ ⟨n, m⟩ ∈ putnam_1998_b4_solution := sorry
4d0808f28adff9ad
putnam_2005_a3
theorem putnam_2005_a3 (p : Polynomial β„‚) (n : β„•) (hn : 0 < n) (g : β„‚ β†’ β„‚) (pdeg : p.degree = n) (pzeros : βˆ€ z : β„‚, p.eval z = 0 β†’ Complex.abs z = 1) (hg : βˆ€ z : β„‚, g z = (p.eval z) / z ^ ((n : β„‚) / 2)) (z : β„‚) (hz : z β‰  0 ∧ deriv g z = 0) : Complex.abs z = 1 := sorry
617b8318eedcb90d
putnam_2015_a3
abbrev putnam_2015_a3_solution : β„‚ := sorry -- 13725 /-- Compute $\log_2 \left( \prod_{a=1}^{2015}\prod_{b=1}^{2015}(1+e^{2\pi iab/2015}) \right)$. Here $i$ is the imaginary unit (that is, $i^2=-1$). -/ theorem putnam_2015_a3 : Complex.log (∏ a : Fin 2015, ∏ b : Fin 2015, (1 + Complex.exp (2 * Real.pi * Complex.I * (a.1 + 1) * (b.1 + 1) / 2015))) / Complex.log 2 = putnam_2015_a3_solution := sorry
26c2ef115ab429e9
putnam_1962_a6
theorem putnam_1962_a6 (S : Set β„š) (hSadd : βˆ€ a ∈ S, βˆ€ b ∈ S, a + b ∈ S) (hSprod : βˆ€ a ∈ S, βˆ€ b ∈ S, a * b ∈ S) (hScond : βˆ€ r : β„š, (r ∈ S ∨ -r ∈ S ∨ r = 0) ∧ Β¬(r ∈ S ∧ -r ∈ S) ∧ Β¬(r ∈ S ∧ r = 0) ∧ Β¬(-r ∈ S ∧ r = 0)) : S = { r : β„š | r > 0 } := sorry
6f565cc92cef6182
putnam_1972_a6
theorem putnam_1972_a6 (f : ℝ β†’ ℝ) (n : β„€) (hn : n β‰₯ 0) (hfintegrable: IntegrableOn f (Icc 0 1)) (hfint : βˆ€ i ∈ Icc 0 (n-1), ∫ x in Icc 0 1, x^i*(f x) = 0) (hfintlast : ∫ x in Icc 0 1, x^n*(f x) = 1) : βˆƒ S, S βŠ† Icc (0 : ℝ) 1 ∧ MeasurableSet S ∧ volume S > 0 ∧ βˆ€ x ∈ S, |f x| β‰₯ 2^n * (n + 1) := sorry
467de9b23c916ce1
putnam_1980_a3
abbrev putnam_1980_a3_solution : ℝ := sorry -- Real.pi / 4 /-- Evaluate $\int_0^{\pi/2}\frac{dx}{1+(\tan x)^{\sqrt{2}}}$. -/ theorem putnam_1980_a3 : ∫ x in Set.Ioo 0 (Real.pi / 2), 1 / (1 + (Real.tan x) ^ (Real.sqrt 2)) = putnam_1980_a3_solution := sorry
12b5470035d85430
putnam_2009_b6
theorem putnam_2009_b6 (n : β„•) (npos : n > 0) : (βˆƒ a : β„• β†’ β„€, a 0 = 0 ∧ a 2009 = n ∧ βˆ€ i : Icc 1 2009, ((βˆƒ j k : β„•, j < i ∧ a i = a j + 2 ^ k) ∨ βˆƒ b c : β„•, b < i ∧ c < i ∧ a b > 0 ∧ a c > 0 ∧ a i = (a b) % (a c))) := sorry
7508f02673138a69
putnam_2019_b6
abbrev putnam_2019_b6_solution : Set β„• := sorry -- Set.Ici 1 /-- Let \( \mathbb{Z}^n \) be the integer lattice in \( \mathbb{R}^n \). Two points in \( \mathbb{Z}^n \) are called neighbors if they differ by exactly 1 in one coordinate and are equal in all other coordinates. For which integers \( n \geq 1 \) does there exist a set of points \( S \subset \mathbb{Z}^n \) satisfying the following two conditions? \begin{enumerate} \item If \( p \) is in \( S \), then none of the neighbors of \( p \) is in \( S \). \item If \( p \in \mathbb{Z}^n \) is not in \( S \), then exactly one of the neighbors of \( p \) is in \( S \). \end{enumerate} -/ theorem putnam_2019_b6 (n : β„•) (neighbors : (Fin n β†’ β„€) β†’ (Fin n β†’ β„€) β†’ Prop) (neighbors_def : βˆ€ p q, neighbors p q ↔ (βˆƒ i : Fin n, abs (p i - q i) = 1 ∧ βˆ€ j β‰  i, p j = q j)) : (1 ≀ n ∧ βˆƒ S : Set (Fin n β†’ β„€), (βˆ€ p ∈ S, βˆ€ q, neighbors p q β†’ q βˆ‰ S) ∧ (βˆ€ p βˆ‰ S, {q ∈ S | neighbors p q}.encard = 1)) ↔ n ∈ putnam_2019_b6_solution := sorry
4f4d4be03d5e8621
putnam_1983_a5
abbrev putnam_1983_a5_solution : Prop := sorry -- True /-- Prove or disprove that there exists a positive real number $\alpha$ such that $[\alpha_n] - n$ is even for all integers $n > 0$. (Here $[x]$ denotes the greatest integer less than or equal to $x$.) -/ theorem putnam_1983_a5 : (βˆƒ Ξ± : ℝ, Ξ± > 0 ∧ βˆ€ n : β„•, n > 0 β†’ Even (⌊α ^ nβŒ‹ - n)) ↔ putnam_1983_a5_solution := sorry
f75e91361943c6d6
putnam_1993_a5
theorem putnam_1993_a5 : ¬Irrational ((∫ x in Set.Ioo (-100) (-10), (((x ^ 2 - x) / (x ^ 3 - 3 * x + 1)) ^ 2)) + (∫ x in Set.Ioo (1 / 101) (1 / 11), (((x ^ 2 - x) / (x ^ 3 - 3 * x + 1)) ^ 2)) + (∫ x in Set.Ioo (101 / 100) (11 / 10), (((x ^ 2 - x) / (x ^ 3 - 3 * x + 1)) ^ 2))) := sorry
e8d5e93e7ca4a55b
putnam_2016_a5
theorem putnam_2016_a5 (G : Type*) [Group G] (Gfin : Fintype G) (g h : G) (ghgen : Subgroup.closure {g, h} = ⊀ ∧ Β¬Subgroup.closure {g} = ⊀ ∧ Β¬Subgroup.closure {h} = ⊀) (godd : Odd (orderOf g)) (S : Set G) (hS : S = {g * h, g⁻¹ * h, g * h⁻¹, g⁻¹ * h⁻¹}) : (βˆ€ x : G, βˆƒ mn : List G, 1 ≀ mn.length ∧ mn.length ≀ Gfin.card ∧ βˆ€ i : Fin mn.length, mn.get i ∈ S ∧ x = List.prod mn) := sorry
a543fa9d2ec27ed1
putnam_2006_a5
abbrev putnam_2006_a5_solution : β„• β†’ β„€ := sorry -- (fun n : β„• => if (n ≑ 1 [MOD 4]) then n else -n) /-- Let $n$ be a positive odd integer and let $\theta$ be a real number such that $\theta/\pi$ is irrational. Set $a_k=\tan(\theta+k\pi/n)$, $k=1,2,\dots,n$. Prove that $\frac{a_1+a_2+\cdots+a_n}{a_1a_2 \cdots a_n}$ is an integer, and determine its value. -/ theorem putnam_2006_a5 (n : β„•) (theta : ℝ) (a : Set.Icc 1 n β†’ ℝ) (nodd : Odd n) (thetairr : Irrational (theta / Real.pi)) (ha : βˆ€ k : Set.Icc 1 n, a k = Real.tan (theta + (k * Real.pi) / n)) : (βˆ‘ k : Set.Icc 1 n, a k) / (∏ k : Set.Icc 1 n, a k) = putnam_2006_a5_solution n := sorry
affc74b16c681580
putnam_2024_b1
abbrev putnam_2024_b1_solution : Set (β„• Γ— β„•) := sorry --{(2*l+1, l+1) | (l : β„•)} /-- Let $n$ and $k$ be positive integers. The square in the $i$th row and $j$th column of an $n$-by-$n$ grid contains the number $i + j - k$. For which $n$ and $k$ is it possible to select $n$ squares from the grid, no two in the same row or column, such that the numbers contained in the selected squares are exactly $1, ..., n$? -/ theorem putnam_2024_b1 (grid : (n : β„•) β†’ β„• β†’ Fin n β†’ Fin n β†’ β„€) (grid_def : βˆ€ n k i j, grid n k i j = i.succ + j.succ - k) (valid : β„• β†’ β„• β†’ Prop) (valid_def : βˆ€ n k, valid n k ↔ 0 < n ∧ 0 < k ∧ βˆƒ (f : Fin n β†’ Fin n), f.Injective ∧ Set.range (fun i => grid n k i (f i)) = Set.Icc (1 : β„€) n) : { (n, k) | valid n k } = putnam_2024_b1_solution := sorry
47b75d05243e5072
putnam_2011_a1
abbrev putnam_2011_a1_solution : β„• := sorry -- 10053 /-- Define a \emph{growing spiral} in the plane to be a sequence of points with integer coordinates $P_0=(0,0),P_1,\dots,P_n$ such that $n \geq 2$ and: \begin{itemize} \item the directed line segments $P_0P_1,P_1P_2,\dots,P_{n-1}P_n$ are in the successive coordinate directions east (for $P_0P_1$), north, west, south, east, etc.; \item the lengths of these line segments are positive and strictly increasing. \end{itemize} How many of the points $(x,y)$ with integer coordinates $0 \leq x \leq 2011,0 \leq y \leq 2011$ \emph{cannot} be the last point, $P_n$ of any growing spiral? -/ theorem putnam_2011_a1 (IsSpiral : List (Fin 2 β†’ β„€) β†’ Prop) (IsSpiral_def : βˆ€ P, IsSpiral P ↔ P.length β‰₯ 3 ∧ P[0]! = 0 ∧ (βˆƒ l : Fin (P.length - 1) β†’ β„•, l > 0 ∧ StrictMono l ∧ (βˆ€ i : Fin (P.length - 1), (i.1 % 4 = 0 β†’ (P[i] 0 + l i = P[i.1 + 1]! 0 ∧ P[i] 1 = P[i.1 + 1]! 1)) ∧ (i.1 % 4 = 1 β†’ (P[i] 0 = P[i.1 + 1]! 0 ∧ P[i] 1 + l i = P[i.1 + 1]! 1)) ∧ (i.1 % 4 = 2 β†’ (P[i] 0 - l i = P[i.1 + 1]! 0 ∧ P[i] 1 = P[i.1 + 1]! 1)) ∧ (i.1 % 4 = 3 β†’ (P[i] 0 = P[i.1 + 1]! 0 ∧ P[i] 1 - l i = P[i.1 + 1]! 1))))) : {p | 0 ≀ p 0 ∧ p 0 ≀ 2011 ∧ 0 ≀ p 1 ∧ p 1 ≀ 2011 ∧ Β¬βˆƒ spiral, IsSpiral spiral ∧ spiral.getLast! = p}.encard = putnam_2011_a1_solution := sorry
e072c73f8942ea7f
putnam_2001_a1
theorem putnam_2001_a1 (S : Type*) [Mul S] (hS : βˆ€ a b : S, (a * b) * a = b) : βˆ€ a b : S, a * (b * a) = b := sorry
6958719999ea03ee
putnam_1976_a4
abbrev putnam_1976_a4_solution : (ℝ β†’ ℝ) Γ— (ℝ β†’ ℝ) := sorry -- (fun r : ℝ => -1/(r + 1), fun r : ℝ => -(r + 1)/r) /-- Let $r$ be a real root of $P(x) = x^3 + ax^2 + bx - 1$, where $a$ and $b$ are integers and $P$ is irreducible over the rationals. Suppose that $r + 1$ is a root of $x^3 + cx^2 + dx + 1$, where $c$ and $d$ are also integers. Express another root $s$ of $P$ as a function of $r$ that does not depend on the values of $a$, $b$, $c$, or $d$. -/ theorem putnam_1976_a4 (a b c d : β„€) (r : ℝ) (P Q: Polynomial β„š) (hP : P = X^3 + (C (a : β„š))*X^2 + (C (b : β„š))*X - (C 1) ∧ aeval r P = 0 ∧ Irreducible P) (hQ : Q = X^3 + (C (c : β„š))*X^2 + (C (d : β„š))*X + (C 1) ∧ aeval (r + 1) Q = 0) : βˆƒ s : ℝ, aeval s P = 0 ∧ (s = putnam_1976_a4_solution.1 r ∨ s = putnam_1976_a4_solution.2 r) := sorry
e3ab2d8e284193d9
putnam_2023_b5
abbrev putnam_2023_b5_solution : Set β„• := sorry -- {n : β„• | n = 1 ∨ n ≑ 2 [MOD 4]} /-- Determine which positive integers $n$ have the following property: For all integers $m$ that are relatively prime to $n$, there exists a permutation $\pi:\{1,2,\dots,n\} \to \{1,2,\dots,n\}$ such that $\pi(\pi(k)) \equiv mk \pmod{n}$ for all $k \in \{1,2,\dots,n\}$. -/ theorem putnam_2023_b5 (n : β„•) : n ∈ putnam_2023_b5_solution ↔ 0 < n ∧ (βˆ€ m : β„€, IsRelPrime m n β†’ βˆƒ p : Equiv.Perm (Fin n), βˆ€ k : Fin n, (p (p k)).1 + 1 ≑ m * (k.1 + 1) [ZMOD n]) := sorry
8b68c4555ecedc62
putnam_1966_a4
theorem putnam_1966_a4 (a : β„• β†’ β„€) (ha1 : a 1 = 2) (hai : βˆ€ n β‰₯ 1, a (n + 1) = (if βˆƒ m : β„€, m^2 = a n + 1 = True then a n + 2 else a n + 1)) : βˆ€ n β‰₯ 1, a n = n + round (Real.sqrt n) := sorry
f2774e3723a1b6ce
putnam_1994_a1
theorem putnam_1994_a1 (a : β„• β†’ ℝ) (ha : βˆ€ n β‰₯ 1, 0 < a n ∧ a n ≀ a (2 * n) + a (2 * n + 1)) : Tendsto (fun N : β„• => βˆ‘ n : Set.Icc 1 N, a n) atTop atTop := sorry
1289f74158047214
putnam_1980_b5
abbrev putnam_1980_b5_solution : ℝ β†’ Prop := sorry -- fun t : ℝ => 1 β‰₯ t /-- A function $f$ is convex on $[0, 1]$ if and only if $$f(su + (1-s)v) \le sf(u) + (1 - s)f(v)$$ for all $s \in [0, 1]$. Let $S_t$ denote the set of all nonnegative increasing convex continuous functions $f : [0, 1] \rightarrow \mathbb{R}$ such that $$f(1) - 2f\left(\frac{2}{3}\right) + f\left(\frac{1}{3}\right) \ge t\left(f\left(\frac{2}{3}\right) - 2f\left(\frac{1}{3}\right) + f(0)\right).$$ For which real numbers $t \ge 0$ is $S_t$ closed under multiplication? -/ theorem putnam_1980_b5 (T : Set ℝ) (hT : T = Icc 0 1) (P : ℝ β†’ (ℝ β†’ ℝ) β†’ Prop) (IsConvex : (ℝ β†’ ℝ) β†’ Prop) (S : ℝ β†’ Set (ℝ β†’ ℝ)) (P_def : βˆ€ t f, P t f ↔ f 1 - 2*f (2/3) + f (1/3) β‰₯ t*(f (2/3) - 2*f (1/3) + f 0)) (IsConvex_def : βˆ€ f, IsConvex f ↔ βˆ€ u ∈ T, βˆ€ v ∈ T, βˆ€ s ∈ T, f (s*u + (1 - s)*v) ≀ s*(f u) + (1 - s)*(f v)) (hS : S = fun t : ℝ => {f : ℝ β†’ ℝ | (βˆ€ x ∈ T, f x β‰₯ 0) ∧ StrictMonoOn f T ∧ IsConvex f ∧ ContinuousOn f T ∧ P t f}) (t : ℝ) (ht : t β‰₯ 0) : putnam_1980_b5_solution t ↔ (βˆ€ f ∈ S t, βˆ€ g ∈ S t, f * g ∈ S t) := sorry
9f672afb597c9673
putnam_1990_b5
abbrev putnam_1990_b5_solution : Prop := sorry -- True /-- Is there an infinite sequence $a_0,a_1,a_2,\dots$ of nonzero real numbers such that for $n=1,2,3,\dots$ the polynomial $p_n(x)=a_0+a_1x+a_2x^2+\cdots+a_nx^n$ has exactly $n$ distinct real roots? -/ theorem putnam_1990_b5 : (βˆƒ a : β„• β†’ ℝ, (βˆ€ i, a i β‰  0) ∧ (βˆ€ n β‰₯ 1, (βˆ‘ i in Finset.Iic n, a i β€’ X ^ i : Polynomial ℝ).roots.toFinset.card = n)) ↔ putnam_1990_b5_solution := sorry
3521530baf9fb098
putnam_2015_b5
abbrev putnam_2015_b5_solution : β„• := sorry -- 4 /-- Let $P_n$ be the number of permutations $\pi$ of $\{1,2,\dots,n\}$ such that \[ |i-j| = 1 \mbox{ implies } |\pi(i) -\pi(j)| \leq 2 \] for all $i,j$ in $\{1,2,\dots,n\}$. Show that for $n \geq 2$, the quantity \[ P_{n+5} - P_{n+4} - P_{n+3} + P_n \] does not depend on $n$, and find its value. -/ theorem putnam_2015_b5 (P : β„• β†’ β„•) (hP : P = fun n ↦ {pi : Finset.Icc 1 n β†’ Finset.Icc 1 n | Bijective pi ∧ βˆ€ i j : Finset.Icc 1 n, Nat.dist i j = 1 β†’ Nat.dist (pi i) (pi j) ≀ 2}.ncard) : (βˆ€ n : β„•, n β‰₯ 2 β†’ (P (n + 5) : β„€) - (P (n + 4) : β„€) - (P (n + 3) : β„€) + (P n : β„€) = putnam_2015_b5_solution) := sorry
058163993a1dea2e
putnam_2005_b5
theorem putnam_2005_b5 (n : β„•) (npos : n > 0) (P : MvPolynomial (Fin n) ℝ) (hderiv : βˆ‘ i : Fin n, (MvPolynomial.pderiv i)^[2] P = 0) (hsumsq : βˆ‘ i : Fin n, (MvPolynomial.X i) ^ 2 ∣ P) : (P = 0) := sorry
7cf42712c896ab48
putnam_1998_a2
theorem putnam_1998_a2 (quadrant : (EuclideanSpace ℝ (Fin 2)) β†’ Prop) (isarc : (EuclideanSpace ℝ (Fin 2)) β†’ (EuclideanSpace ℝ (Fin 2)) β†’ Prop) (hquadrant : βˆ€ P, quadrant P ↔ P 0 > 0 ∧ P 1 > 0 ∧ dist 0 P = 1) (hisarc : βˆ€ P Q, isarc P Q ↔ quadrant P ∧ quadrant Q ∧ P 0 > Q 0) (arc : (EuclideanSpace ℝ (Fin 2)) β†’ (EuclideanSpace ℝ (Fin 2)) β†’ Set (EuclideanSpace ℝ (Fin 2))) (harc : arc = fun P Q ↦ {R : EuclideanSpace ℝ (Fin 2) | quadrant R ∧ P 0 > R 0 ∧ R 0 > Q 0}) (A B : (EuclideanSpace ℝ (Fin 2)) β†’ (EuclideanSpace ℝ (Fin 2)) β†’ ℝ) (hA : A = fun P Q ↦ (MeasureTheory.volume {S : EuclideanSpace ℝ (Fin 2) | βˆƒ R ∈ arc P Q, R 0 = S 0 ∧ R 1 > S 1 ∧ S 1 > 0}).toReal) (hB : B = fun P Q ↦ (MeasureTheory.volume {S : EuclideanSpace ℝ (Fin 2) | βˆƒ R ∈ arc P Q, R 1 = S 1 ∧ R 0 > S 0 ∧ S 0 > 0}).toReal) : (βˆƒ f : ℝ β†’ ℝ, βˆ€ P Q : EuclideanSpace ℝ (Fin 2), isarc P Q β†’ A P Q + B P Q = f (InnerProductGeometry.angle P Q)) := sorry
edbc2f4a8d7d9f95
putnam_1975_b4
abbrev putnam_1975_b4_solution : Prop := sorry -- False /-- Let $C = \{(x, y) \in \mathbb{R}^2 : x^2 + y^2 = 1\}$ denote the unit circle. Does there exist $B \subseteq C$ for which $B$ is topologically closed and contains exactly one point from each pair of diametrically opposite points in $C$? -/ theorem putnam_1975_b4 (P : ℝ Γ— ℝ β†’ Prop) (hP : P = fun (x, y) => x^2 + y^2 = 1) : (βˆƒ B βŠ† setOf P, IsClosed B ∧ βˆ€ x y : ℝ, P (x, y) β†’ Xor' ((x, y) ∈ B) ((-x, -y) ∈ B)) ↔ putnam_1975_b4_solution := sorry
8883ccf8312e64f1
putnam_1988_a2
abbrev putnam_1988_a2_solution : Prop := sorry -- True /-- A not uncommon calculus mistake is to believe that the product rule for derivatives says that $(fg)' = f'g'$. If $f(x)=e^{x^2}$, determine, with proof, whether there exists an open interval $(a,b)$ and a nonzero function $g$ defined on $(a,b)$ such that this wrong product rule is true for $x$ in $(a,b)$. -/ theorem putnam_1988_a2 (f : ℝ β†’ ℝ) (hf : f = fun x ↦ Real.exp (x ^ 2)) : putnam_1988_a2_solution ↔ (βˆƒ a b : ℝ, a < b ∧ βˆƒ g : ℝ β†’ ℝ, (βˆƒ x ∈ Ioo a b, g x β‰  0) ∧ DifferentiableOn ℝ g (Ioo a b) ∧ βˆ€ x ∈ Ioo a b, deriv (fun y ↦ f y * g y) x = (deriv f x) * (deriv g x)) := sorry
d0852f2fd5c40e57
putnam_2020_a5
abbrev putnam_2020_a5_solution : β„€ := sorry -- (Nat.fib 4040) - 1 /-- Let $a_n$ be the number of sets $S$ of positive integers for which \[ \sum_{k \in S} F_k = n, \] where the Fibonacci sequence $(F_k)_{k \geq 1}$ satisfies $F_{k+2} = F_{k+1} + F_k$ and begins $F_1 = 1, F_2 = 1, F_3 = 2, F_4 = 3$. Find the largest integer $n$ such that $a_n = 2020$. -/ theorem putnam_2020_a5 (a : β„€ β†’ β„•) (ha : a = fun n : β„€ => {S : Finset β„• | (βˆ€ k ∈ S, k > 0) ∧ βˆ‘ k : S, Nat.fib k = n}.ncard) : IsGreatest {n | a n = 2020} putnam_2020_a5_solution := sorry
cf3425b1897164f4
putnam_1965_b4
abbrev putnam_1965_b4_solution : ((((ℝ β†’ ℝ) β†’ (ℝ β†’ ℝ)) Γ— ((ℝ β†’ ℝ) β†’ (ℝ β†’ ℝ))) Γ— ((Set ℝ) Γ— (ℝ β†’ ℝ))) := sorry -- ((fun h : ℝ β†’ ℝ => h + (fun x : ℝ => x), fun h : ℝ β†’ ℝ => h + (fun _ : ℝ => 1)), ({x : ℝ | x β‰₯ 0}, Real.sqrt)) /-- Let $$f(x, n) = \frac{{n \choose 0} + {n \choose 2}x + {n \choose 4}x^2 + \cdots}{{n \choose 1} + {n \choose 3}x + {n \choose 5}x^2 + \cdots}$$ for all real numbers $x$ and positive integers $n$. Express $f(x, n+1)$ as a rational function involving $f(x, n)$ and $x$, and find $\lim_{n \to \infty} f(x, n)$ for all $x$ for which this limit converges. -/ theorem putnam_1965_b4 (f u v : β„• β†’ ℝ β†’ ℝ) (hu : βˆ€ n > 0, βˆ€ x, u n x = βˆ‘ i in Finset.Icc 0 (n / 2), (n.choose (2 * i)) * x ^ i) (hv : βˆ€ n > 0, βˆ€ x, v n x = βˆ‘ i in Finset.Icc 0 ((n - 1) / 2), (n.choose (2 * i + 1)) * x ^ i) (hf : βˆ€ n > 0, βˆ€ x, f n x = u n x / v n x) (n : β„•) (hn : 0 < n) : let ⟨⟨p, q⟩, ⟨s, g⟩⟩ := putnam_1965_b4_solution (βˆ€ x, v n x β‰  0 β†’ v (n + 1) x β‰  0 β†’ q (f n) x β‰  0 β†’ f (n + 1) x = p (f n) x / q (f n) x) ∧ s = {x | βˆƒ l, Tendsto (fun n ↦ f n x) atTop (𝓝 l)} ∧ βˆ€ x ∈ s, Tendsto (fun n ↦ f n x) atTop (𝓝 (g x)) := sorry
aa54494f6a069281
putnam_2012_b1
theorem putnam_2012_b1 (S : Set (Set.Ici (0 : ℝ) β†’ ℝ)) (rngS : βˆ€ f ∈ S, βˆ€ x : Set.Ici (0 : ℝ), f x ∈ Set.Ici (0 : ℝ)) (f1 : Set.Ici (0 : ℝ) β†’ ℝ) (hf1 : f1 = fun (x : Set.Ici (0 : ℝ)) ↦ exp x - 1) (f2 : Set.Ici (0 : ℝ) β†’ ℝ) (hf2 : f2 = fun (x : Set.Ici (0 : ℝ)) ↦ Real.log (x + 1)) (hf1mem : f1 ∈ S) (hf2mem : f2 ∈ S) (hsum : βˆ€ f ∈ S, βˆ€ g ∈ S, (fun x ↦ (f x) + (g x)) ∈ S) (hcomp : βˆ€ f ∈ S, βˆ€ g ∈ S, βˆ€ gnneg : Set.Ici (0 : ℝ) β†’ Set.Ici (0 : ℝ), ((βˆ€ x : Set.Ici (0 : ℝ), g x = gnneg x) β†’ (fun x ↦ f (gnneg x)) ∈ S)) (hdiff : βˆ€ f ∈ S, βˆ€ g ∈ S, (βˆ€ x : Set.Ici (0 : ℝ), f x β‰₯ g x) β†’ (fun x ↦ (f x) - (g x)) ∈ S) : (βˆ€ f ∈ S, βˆ€ g ∈ S, (fun x ↦ (f x) * (g x)) ∈ S) := sorry
108f0abe029c5fde
putnam_1987_b1
abbrev putnam_1987_b1_solution : ℝ := sorry -- 1 /-- Evaluate \[ \int_2^4 \frac{\sqrt{\ln(9-x)}\,dx}{\sqrt{\ln(9-x)}+\sqrt{\ln(x+3)}}. \] -/ theorem putnam_1987_b1 : (∫ x in (2)..4, sqrt (log (9 - x)) / (sqrt (log (9 - x)) + sqrt (log (x + 3))) = putnam_1987_b1_solution) := sorry
a347b5725a26d120
putnam_1997_b1
abbrev putnam_1997_b1_solution : β„• β†’ ℝ := sorry -- fun n => n noncomputable def dist_to_int : ℝ β†’ ℝ := fun r => |r - round r| /-- Let $\{x\}$ denote the distance between the real number $x$ and the nearest integer. For each positive integer $n$, evaluate \[F_n=\sum_{m=1}^{6n-1} \min(\{\frac{m}{6n}\},\{\frac{m}{3n}\}).\] (Here $\min(a,b)$ denotes the minimum of $a$ and $b$.) -/ theorem putnam_1997_b1 (F : β„• β†’ ℝ) (hF : F = fun (n : β„•) => βˆ‘ m in Finset.Icc 1 (6 * n - 1), min (dist_to_int (m/(6*n)) ) (dist_to_int (m/(3*n)))) : βˆ€ n, n > 0 β†’ F n = putnam_1997_b1_solution n := sorry
5bd3e81075dd3306
putnam_1979_a1
abbrev putnam_1979_a1_solution : Multiset β„• := sorry -- Multiset.replicate 659 3 + {2} /-- For which positive integers $n$ and $a_1, a_2, \dots, a_n$ with $\sum_{i = 1}^{n} a_i = 1979$ does $\prod_{i = 1}^{n} a_i$ attain the greatest value? -/ theorem putnam_1979_a1 (P : Multiset β„• β†’ Prop) (hP : βˆ€ a, P a ↔ Multiset.card a > 0 ∧ (βˆ€ i ∈ a, i > 0) ∧ a.sum = 1979) : P putnam_1979_a1_solution ∧ βˆ€ a : Multiset β„•, P a β†’ putnam_1979_a1_solution.prod β‰₯ a.prod := sorry
e8978e84d7f5ee7e
putnam_1969_a1
abbrev putnam_1969_a1_solution : Set (Set ℝ) := sorry -- {{x} | x : ℝ} βˆͺ {Set.Ici x | x : ℝ} βˆͺ {Set.Iic x | x : ℝ} βˆͺ {Set.Iio x | x : ℝ} βˆͺ {Set.Ioi x | x : ℝ} βˆͺ {Set.univ} /-- What are the possible ranges (across all real inputs $x$ and $y$) of a polynomial $f(x, y)$ with real coefficients? -/ theorem putnam_1969_a1 : {{z : ℝ | βˆƒ x : Fin 2 β†’ ℝ, MvPolynomial.eval x f = z} | f : MvPolynomial (Fin 2) ℝ} = putnam_1969_a1_solution := sorry
ff753e018045e9be
putnam_1966_b2
theorem putnam_1966_b2 (S : β„€ β†’ Set β„€) (hS : S = fun n : β„€ => {n, n + 1, n + 2, n + 3, n + 4, n + 5, n + 6, n + 7, n + 8, n + 9}) : βˆ€ n : β„€, n > 0 β†’ (βˆƒ k ∈ S n, βˆ€ m ∈ S n, k β‰  m β†’ IsCoprime m k) := sorry
35bb601cf2f0caf3
putnam_2023_a3
abbrev putnam_2023_a3_solution : ℝ := sorry -- Real.pi / 2 /-- Determine the smallest positive real number $r$ such that there exist differentiable functions $f\colon \mathbb{R} \to \mathbb{R}$ and $g\colon \mathbb{R} \to \mathbb{R}$ satisfying \begin{enumerate} \item[(a)] $f(0) > 0$, \item[(b)] $g(0) = 0$, \item[(c)] $|f'(x)| \leq |g(x)|$ for all $x$, \item[(d)] $|g'(x)| \leq |f(x)|$ for all $x$, and \item[(e)] $f(r) = 0$. \end{enumerate} -/ theorem putnam_2023_a3 : sInf {r > 0 | βˆƒ f g : ℝ β†’ ℝ, Differentiable ℝ f ∧ Differentiable ℝ g ∧ (βˆ€ x : ℝ, |deriv f x| ≀ |g x| ∧ |deriv g x| ≀ |f x|) ∧ f 0 > 0 ∧ g 0 = 0 ∧ f r = 0} = putnam_2023_a3_solution := sorry
4724b10205cfca70
putnam_1976_b2
abbrev putnam_1976_b2_solution : β„• Γ— Set (List (β„€ Γ— β„€)) := sorry -- (8, {[(0, 0)], [(2, 0)], [(0, 1)], [(0, 2)], [(0, 3)], [(0, 4)], [(0, 5)], [(0, 6)]}) /-- Let $G$ be a group generated by two elements $A$ and $B$; i.e., every element of $G$ can be expressed as a finite word $A^{n_1}B^{n_2} \cdots A^{n_{k-1}}B^{n_k}$, where the $n_i$ can assume any integer values and $A^0 = B^0 = 1$. Further assume that $A^4 = B^7 = ABA^{-1}B = 1$, but $A^2 \ne 1$ and $B \ne 1$. Find the number of elements of $G$ than can be written as $C^2$ for some $C \in G$ and express each such square as a word in $A$ and $B$. -/ theorem putnam_1976_b2 (G : Type*) [Group G] (A B : G) (word : List (β„€ Γ— β„€) β†’ G) (hword : word = fun w : List (β„€ Γ— β„€) => (List.map (fun t : β„€ Γ— β„€ => A^(t.1)*B^(t.2)) w).prod) (hG : βˆ€ g : G, βˆƒ w : List (β„€ Γ— β„€), g = word w) (hA : A^4 = 1 ∧ A^2 β‰  1) (hB : B^7 = 1 ∧ B β‰  1) (h1 : A*B*A^(-(1 : β„€))*B = 1) (S : Set G) (hS : S = {g : G | βˆƒ C : G, C^2 = g}) : S.ncard = putnam_1976_b2_solution.1 ∧ S = {word w | w ∈ putnam_1976_b2_solution.2} := sorry
de2aed7f95f0feb7
putnam_1971_b6
theorem putnam_1971_b6 (Ξ΄ : β„€ β†’ β„€) (hΞ΄ : Ξ΄ = fun n => sSup {t | Odd t ∧ t ∣ n}) : βˆ€ x : β„€, x > 0 β†’ |βˆ‘ i in Finset.Icc 1 x, (Ξ΄ i)/(i : β„š) - 2*x/3| < 1 := sorry
8d08b04315529ab6
putnam_2006_b3
abbrev putnam_2006_b3_solution : β„• β†’ β„• := sorry -- (fun n : β„• => (Nat.choose n 2) + 1) /-- Let $S$ be a finite set of points in the plane. A linear partition of $S$ is an unordered pair $\{A,B\}$ of subsets of $S$ such that $A \cup B=S$, $A \cap B=\emptyset$, and $A$ and $B$ lie on opposite sides of some straight line disjoint from $S$ ($A$ or $B$ may be empty). Let $L_S$ be the number of linear partitions of $S$. For each positive integer $n$, find the maximum of $L_S$ over all sets $S$ of $n$ points. -/ theorem putnam_2006_b3 (IsLinearPartition : Finset (Fin 2 β†’ ℝ) β†’ Finset (Finset (Fin 2 β†’ ℝ)) β†’ Prop) (IsLinearPartition_def : βˆ€ S AB, IsLinearPartition S AB ↔ (AB.card = 2 ∧ βˆƒ A ∈ AB, βˆƒ B ∈ AB, A β‰  B ∧ (A βˆͺ B = S) ∧ (A ∩ B = βˆ…) ∧ (βˆƒ m b : ℝ, (βˆ€ p ∈ A, p 1 > m * p 0 + b) ∧ (βˆ€ p ∈ B, p 1 < m * p 0 + b)))) (L : Finset (Fin 2 β†’ ℝ) β†’ β„•) (hL : βˆ€ S, L S = {AB | IsLinearPartition S AB}.encard) (n : β„•) (npos : 0 < n) : IsGreatest {L S | (S) (hS : S.card = n)} (putnam_2006_b3_solution n) := sorry
db27465358ae78eb
putnam_2016_b3
theorem putnam_2016_b3 (S : Finset (Fin 2 β†’ ℝ)) (hS : βˆ€ A ∈ S, βˆ€ B ∈ S, βˆ€ C ∈ S, MeasureTheory.volume (convexHull ℝ {A, B, C}) ≀ 1) : βˆƒ A' B' C' : Fin 2 β†’ ℝ, MeasureTheory.volume (convexHull ℝ {A', B', C'}) = 4 ∧ convexHull ℝ {A', B', C'} βŠ‡ S := sorry
034e637da2727cb6
putnam_1993_b3
abbrev putnam_1993_b3_solution : β„š Γ— β„š := sorry -- (5 / 4, -1 / 4) /-- Two real numbers $x$ and $y$ are chosen at random in the interval $(0,1)$ with respect to the uniform distribution. What is the probability that the closest integer to $x/y$ is even? Express the answer in the form $r+s\pi$, where $r$ and $s$ are rational numbers. -/ theorem putnam_1993_b3 : let (r, s) := putnam_1993_b3_solution; (MeasureTheory.volume {p : Fin 2 β†’ ℝ | 0 < p ∧ p < 1 ∧ Even (round (p 0 / p 1))} ).toReal = r + s * Real.pi := sorry
d64ec33e9c311628
putnam_2010_b6
theorem putnam_2010_b6 (n : β„•) (npos : n β‰₯ 1) (A : Matrix (Fin n) (Fin n) ℝ) (Apow : β„• β†’ Matrix (Fin n) (Fin n) ℝ) (hApow : βˆ€ k > 0, Apow k = (fun i j : Fin n => (A i j) ^ k)) : (βˆ€ k ∈ Set.Icc 1 (n + 1), A ^ k = Apow k) β†’ (βˆ€ k β‰₯ 1, A ^ k = Apow k) := sorry
19bb4e7341655210
putnam_1977_b3
abbrev putnam_1977_b3_solution : Prop := sorry -- False /-- An ordered triple $(a, b, c)$ of positive irrational numbers with $a + b + c = 1$ is considered $\textit{balanced}$ if all three elements are less than $\frac{1}{2}$. If a triple is not balanced, we can perform a ``balancing act'' $B$ defined by $B(a, b, c) = (f(a), f(b), f(c))$, where $f(x) = 2x - 1$ if $x > 1/2$ and $f(x) = 2x$ otherwise. Will finitely many iterations of this balancing act always eventually produce a balanced triple? -/ theorem putnam_1977_b3 (P balanced: ℝ Γ— ℝ Γ— ℝ β†’ Prop) (B : ℝ Γ— ℝ Γ— ℝ β†’ ℝ Γ— ℝ Γ— ℝ) (hP : P = fun (a, b, c) => Irrational a ∧ Irrational b ∧ Irrational c ∧ a > 0 ∧ b > 0 ∧ c > 0 ∧ a + b + c = 1) (hbalanced : balanced = fun (a, b, c) => a < 1/2 ∧ b < 1/2 ∧ c < 1/2) (hB : B = fun (a, b, c) => (ite (a > 1/2) (2*a - 1) (2*a), ite (b > 1/2) (2*b - 1) (2*b), ite (c > 1/2) (2*c - 1) (2*c))) : (βˆ€ t : ℝ Γ— ℝ Γ— ℝ, P t β†’ βˆƒ n : β„•, balanced (B^[n] t)) ↔ putnam_1977_b3_solution := sorry
e97219934df9a5c5
putnam_2022_a2
abbrev putnam_2022_a2_solution : β„• β†’ β„• := sorry -- fun n => 2*n - 2 /-- Let $n$ be an integer with $n \geq 2$. Over all real polynomials $p(x)$ of degree $n$, what is the largest possible number of negative coefficients of $p(x)^2$? -/ theorem putnam_2022_a2 (n : β„•) (hn : n β‰₯ 2) (S : Set ℝ[X]) (hS : S = {P | natDegree P = n}) (negs : ℝ[X] β†’ β„•) (hnegs : βˆ€ P : ℝ[X], negs P = βˆ‘ i in Finset.range (P.natDegree + 1), if P.coeff i < 0 then 1 else 0) : sSup {negs (P^2) | P ∈ S} = putnam_2022_a2_solution n := sorry
ec96680e03bd2ff6
putnam_1967_b3
theorem putnam_1967_b3 (f g : ℝ β†’ ℝ) (fgcont : Continuous f ∧ Continuous g) (fgperiod : Function.Periodic f 1 ∧ Function.Periodic g 1) : Tendsto (fun n : β„€ => ∫ x in Set.Ioo 0 1, f x * g (n * x)) atTop (𝓝 ((∫ x in Set.Ioo 0 1, f x) * (∫ x in Set.Ioo 0 1, g x))) := sorry
23bcf79916c4033c
putnam_1985_b6
theorem putnam_1985_b6 (n : β„•) (npos : n > 0) (G : Finset (Matrix (Fin n) (Fin n) ℝ)) (groupG : (βˆ€ g ∈ G, βˆ€ h ∈ G, g * h ∈ G) ∧ 1 ∈ G ∧ (βˆ€ g ∈ G, βˆƒ h ∈ G, g * h = 1)) (hG : βˆ‘ M in G, Matrix.trace M = 0) : (βˆ‘ M in G, M = 0) := sorry
c9538cd13c8765d1
putnam_1995_b6
theorem putnam_1995_b6 (S : ℝ β†’ Set β„•) (hS : S = fun (Ξ± : ℝ) => {x : β„• | βˆƒ n : β„•, n β‰₯ 1 ∧ x = floor (n * Ξ±)}) : Β¬ βˆƒ Ξ± Ξ² Ξ³, Ξ± > 0 ∧ Ξ² > 0 ∧ Ξ³ > 0 ∧ (S Ξ±) ∩ (S Ξ²) = βˆ… ∧ (S Ξ²) ∩ (S Ξ³) = βˆ… ∧ (S Ξ±) ∩ (S Ξ³) = βˆ… ∧ Set.Ici 1 = (S Ξ±) βˆͺ (S Ξ²) βˆͺ (S Ξ³) := sorry
076c5abea64bdd8a
putnam_2008_a1
theorem putnam_2008_a1 (f : ℝ β†’ ℝ β†’ ℝ) (hf : βˆ€ x y z : ℝ, f x y + f y z + f z x = 0) : βˆƒ g : ℝ β†’ ℝ, βˆ€ x y : ℝ, f x y = g x - g y := sorry
eab40aa77c2eb040
putnam_2018_a1
abbrev putnam_2018_a1_solution : Set (β„€ Γ— β„€) := sorry -- {⟨673, 1358114⟩, ⟨674, 340033⟩, ⟨1009, 2018⟩, ⟨2018, 1009⟩, ⟨340033, 674⟩, ⟨1358114, 673⟩} /-- Find all ordered pairs $(a,b)$ of positive integers for which $\frac{1}{a} + \frac{1}{b} = \frac{3}{2018}$. -/ theorem putnam_2018_a1 (a b : β„€) (h : 0 < a ∧ 0 < b) : ((1 : β„š) / a + (1 : β„š) / b = (3 : β„š) / 2018) ↔ (⟨a, b⟩ ∈ putnam_2018_a1_solution) := sorry
4da0c14353099928
putnam_1982_b2
abbrev putnam_1982_b2_solution : Polynomial ℝ := sorry -- C Real.pi * (2*X - 1)^2 /-- Let $A(x, y)$ denote the number of points $(m, n)$ with integer coordinates $m$ and $n$ where $m^2 + n^2 \le x^2 + y^2$. Also, let $g = \sum_{k = 0}^{\infty} e^{-k^2}$. Express the value $$\int_{-\infty}^{\infty}\int_{-\infty}^{\infty} A(x, y)e^{-x^2 - y^2} dx dy$$ as a polynomial in $g$. -/ theorem putnam_1982_b2 (A : ℝ Γ— ℝ β†’ β„•) (g I : ℝ) (hA : A = fun (x, y) => {(m, n) : β„€ Γ— β„€ | m^2 + n^2 ≀ x^2 + y^2}.ncard) (hg : g = βˆ‘' k : β„•, Real.exp (-k^2)) (hI : I = ∫ y : ℝ, ∫ x : ℝ, A (x, y) * Real.exp (-x^2 - y^2)) : I = putnam_1982_b2_solution.eval g := sorry
8f7a6b32376ab494
putnam_1992_b2
theorem putnam_1992_b2 (Q : β„• β†’ β„• β†’ β„•) (hQ : Q = fun n k ↦ coeff ((1 + X + X ^ 2 + X ^ 3) ^ n) k) (n k : β„•) : Q n k = βˆ‘ j in Finset.Iic k, choose n j * (if 2 * j ≀ k then choose n (k - 2 * j) else 0) := sorry
7859590c71b5bc24
putnam_2017_b2
abbrev putnam_2017_b2_solution : β„• := sorry -- 16 /-- Suppose that a positive integer $N$ can be expressed as the sum of $k$ consecutive positive integers \[ N = a + (a+1) +(a+2) + \cdots + (a+k-1) \] for $k=2017$ but for no other values of $k>1$. Considering all positive integers $N$ with this property, what is the smallest positive integer $a$ that occurs in any of these expressions? -/ theorem putnam_2017_b2 (S : β„€ β†’ β„• β†’ β„€) (p : β„€ β†’ β„• β†’ Prop) (q : β„€ β†’ Prop) (hS : S = fun (a : β„€) k ↦ βˆ‘ i in Finset.range k, (a + i)) (hp : βˆ€ N k, p N k ↔ βˆƒ a > 0, S a k = N) (hq : βˆ€ N, q N ↔ p N 2017 ∧ βˆ€ k : β„•, k > 1 β†’ k β‰  2017 β†’ Β¬p N k) : IsLeast {a : β„€ | q (S a 2017)} putnam_2017_b2_solution := sorry
373c86091be2689b
putnam_2007_b2
theorem putnam_2007_b2 (f : ℝ β†’ ℝ) (hf : ContDiffOn ℝ 1 f (Icc 0 1)) (hfint : ∫ x in (0)..1, f x = 0) (max : ℝ) (heqmax : βˆƒ x ∈ Icc (0 : ℝ) 1, |deriv f x| = max) (hmaxub : βˆ€ x ∈ Icc (0 : ℝ) 1, |deriv f x| ≀ max) : (βˆ€ Ξ± ∈ (Ioo (0 : ℝ) 1), |∫ x in (0)..Ξ±, f x| ≀ (1 / 8) * max) := sorry
98b78a7cff5249c2
putnam_2004_b4
abbrev putnam_2004_b4_solution : β„• β†’ β„‚ β†’ β„‚ := sorry -- fun n z ↦ z + n /-- Let $n$ be a positive integer, $n \ge 2$, and put $\theta = 2 \pi / n$. Define points $P_k = (k,0)$ in the $xy$-plane, for $k = 1, 2, \dots, n$. Let $R_k$ be the map that rotates the plane counterclockwise by the angle $\theta$ about the point $P_k$. Let $R$ denote the map obtained by applying, in order, $R_1$, then $R_2, \dots$, then $R_n$. For an arbitrary point $(x,y)$, find, and simplify, the coordinates of $R(x,y)$. -/ theorem putnam_2004_b4 (n : β„•) (nge2 : n β‰₯ 2) (R Rk : β„• β†’ β„‚ β†’ β„‚) (hR : R 0 = id ∧ βˆ€ k : β„•, R (k + 1) = Rk (k + 1) ∘ R k) (hRk : Rk = fun (k : β„•) (Q : β„‚) ↦ k + Complex.exp (Complex.I * 2 * Real.pi / n) * (Q - k)) : (R n = putnam_2004_b4_solution n) := sorry
561daef8fae6dfcb
putnam_2014_b4
theorem putnam_2014_b4 (n : β„•) (P: Polynomial β„‚) (npos : n > 0) (Px : P.degree = n ∧ βˆ€ k ∈ Set.Icc 0 n, P.coeff k = 2 ^ (k * (n - k))) : βˆ€ r ∈ P.roots, r.im = 0 := sorry
01fb7b3d7113347a
putnam_1963_b1
abbrev putnam_1963_b1_solution : β„€ := sorry -- 2 /-- For what integer $a$ does $x^2-x+a$ divide $x^{13}+x+90$? -/ theorem putnam_1963_b1 : βˆ€ a : β„€, (X^2 - X + (C a)) ∣ (X ^ 13 + X + (C 90)) ↔ a = putnam_1963_b1_solution := sorry
c5e5393838a15bf2
putnam_1973_b1
theorem putnam_1973_b1 (n : β„•) (a : Finset.Icc 1 (2 * n + 1) β†’ β„€) (h_remove : βˆ€ S : Finset (Finset.Icc 1 (2 * n + 1)), S.card = 2*n β†’ βˆƒ T, T βŠ† S ∧ T.card = n ∧ βˆ‘ i in T, a i = βˆ‘ i in (S \ T), a i) : βˆ€ i j : Finset.Icc 1 (2 * n + 1), a i = a j := sorry
76098aa58176ac9a
putnam_1991_b4
theorem putnam_1991_b4 (p : β„•) (podd : Odd p) (pprime : Prime p) : (βˆ‘ j : Fin (p + 1), (p.choose j) * ((p + j).choose j)) ≑ (2 ^ p + 1) [MOD (p ^ 2)] := sorry
07843bc3544afc32
putnam_1981_b4
abbrev putnam_1981_b4_solution : Prop := sorry -- False /-- Let $V$ be a set of $5$ by $7$ matrices, with real entries and with the property that $rA+sB \in V$ whenever $A,B \in V$ and $r$ and $s$ are scalars (i.e., real numbers). \emph{Prove or disprove} the following assertion: If $V$ contains matrices of ranks $0$, $1$, $2$, $4$, and $5$, then it also contains a matrix of rank $3$. [The rank of a nonzero matrix $M$ is the largest $k$ such that the entries of some $k$ rows and some $k$ columns form a $k$ by $k$ matrix with a nonzero determinant.] -/ theorem putnam_1981_b4 (VAB : Set (Matrix (Fin 5) (Fin 7) ℝ) β†’ Prop) (Vrank : Set (Matrix (Fin 5) (Fin 7) ℝ) β†’ β„• β†’ Prop) (hVAB : βˆ€ V, VAB V = (βˆ€ A ∈ V, βˆ€ B ∈ V, βˆ€ r s : ℝ, r β€’ A + s β€’ B ∈ V)) (hVrank : βˆ€ V k, Vrank V k = βˆƒ A ∈ V, A.rank = k) : putnam_1981_b4_solution ↔ (βˆ€ V, VAB V β†’ Vrank V 0 β†’ Vrank V 1 β†’ Vrank V 2 β†’ Vrank V 4 β†’ Vrank V 5 β†’ Vrank V 3) := sorry
79ba19c2861f11da
putnam_1964_b5
theorem putnam_1964_b5 (a b : β„• β†’ β„•) (ha : StrictMono a ∧ βˆ€ n : β„•, a n > 0) (hb : b 0 = a 0 ∧ βˆ€ n : β„•, b (n + 1) = lcm (b n) (a (n + 1))) : (βˆƒ L : ℝ, Tendsto (fun N ↦ βˆ‘ n in Finset.range N, (1 : ℝ) / b n) atTop (𝓝 L)) := sorry
be50b373a74a6ea3
putnam_1989_a3
theorem putnam_1989_a3 (z : β„‚) (hz : 11 * z ^ 10 + 10 * I * z ^ 9 + 10 * I * z - 11 = 0) : (β€–zβ€– = 1) := sorry
44470eaaa9d4eb43
putnam_2021_a4
abbrev putnam_2021_a4_solution : ℝ := sorry -- ((Real.sqrt 2) / 2) * Real.pi * Real.log 2 /-- Let \[ I(R) = \iint_{x^2+y^2 \leq R^2} \left( \frac{1+2x^2}{1+x^4+6x^2y^2+y^4} - \frac{1+y^2}{2+x^4+y^4} \right)\,dx\,dy. \] Find \[ \lim_{R \to \infty} I(R), \] or show that this limit does not exist. -/ theorem putnam_2021_a4 (S : ℝ β†’ Set (EuclideanSpace ℝ (Fin 2))) (hS : S = fun R => ball (0 : EuclideanSpace ℝ (Fin 2)) R) (I : ℝ β†’ ℝ) (hI : I = fun R => ∫ p in S R, (1 + 2*(p 0)^2)/(1 + (p 0)^4 + 6*(p 0)^2*(p 1)^2 + (p 1)^4) - (1 + (p 1)^2)/(2 + (p 0)^4 + (p 1)^4)) : Tendsto I atTop (𝓝 putnam_2021_a4_solution) := sorry
ede795b18a7e6da3
putnam_1974_b5
theorem putnam_1974_b5 : βˆ€ n β‰₯ 0, βˆ‘ i in Finset.Icc (0 : β„•) n, (n^i : ℝ)/(Nat.factorial i) > (Real.exp n)/2 := sorry
7f86dc460ad5461f
putnam_1999_a3
theorem putnam_1999_a3 (f : ℝ β†’ ℝ) (hf : f = fun x ↦ 1 / (1 - 2 * x - x ^ 2)) (a : β„• β†’ ℝ) (hf' : βˆ€αΆ  x in 𝓝 0, Tendsto (fun N : β„• ↦ βˆ‘ n in Finset.range N, (a n) * x ^ n) atTop (𝓝 (f x))) (n : β„•) : βˆƒ m : β„•, (a n) ^ 2 + (a (n + 1)) ^ 2 = a m := sorry
271b78e8fdb16719
putnam_1994_a6
theorem putnam_1994_a6 (f : Fin 10 β†’ Equiv.Perm β„€) (mijcomp : β„• β†’ (β„• β†’ Fin 10) β†’ β„• β†’ (β„€ β†’ β„€)) (F : Finset (β„€ β†’ β„€)) (hf: βˆ€ n : β„€, βˆƒ m : β„•, βˆƒ i : β„• β†’ Fin 10, m β‰₯ 1 ∧ (mijcomp m i 0) 0 = n) (hmijcomp : βˆ€ m β‰₯ 1, βˆ€ (i : β„• β†’ Fin 10) (j : Fin m), mijcomp m i j = if (j = m - 1) then (f (i j) : β„€ β†’ β„€) else (f (i j) ∘ mijcomp m i (j + 1))) (hF : F = {g : β„€ β†’ β„€ | βˆƒ e : Fin 10 β†’ Fin 2, g = (f 0)^[e 0] ∘ (f 1)^[e 1] ∘ (f 2)^[e 2] ∘ (f 3)^[e 3] ∘ (f 4)^[e 4] ∘ (f 5)^[e 5] ∘ (f 6)^[e 6] ∘ (f 7)^[e 7] ∘ (f 8)^[e 8] ∘ (f 9)^[e 9]}) : βˆ€ A : Finset β„€, A.Nonempty β†’ {g ∈ F | g '' A = A}.card ≀ 512 := sorry
743c0e8f3075473d
putnam_1984_a6
abbrev putnam_1984_a6_solution : β„• := sorry -- 4 /-- Let $n$ be a positive integer, and let $f(n)$ denote the last nonzero digit in the decimal expansion of $n!$. For instance, $f(5)=2$. \begin{enumerate} \item[(a)] Show that if $a_1,a_2,\dots,a_k$ are \emph{distinct} nonnegative integers, then $f(5^{a_1}+5^{a_2}+\dots+5^{a_k})$ depends only on the sum $a_1+a_2+\dots+a_k$. \item[(b)] Assuming part (a), we can define $g(s)=f(5^{a_1}+5^{a_2}+\dots+5^{a_k})$, where $s=a_1+a_2+\dots+a_k$. Find the least positive integer $p$ for which $g(s)=g(s + p)$, for all $s \geq 1$, or else show that no such $p$ exists. \end{enumerate} -/ theorem putnam_1984_a6 (f : β„• β†’ β„•) (hf : βˆ€ n, some (f n) = (Nat.digits 10 (n !)).find? (fun d ↦ d β‰  0)) (IsPeriodicFrom : β„• β†’ (β„• β†’ β„•) β†’ β„• β†’ Prop) (IsPeriodicFrom_def : βˆ€ x f p, IsPeriodicFrom x f p ↔ Periodic (f ∘ (Β· + x)) p) (P : β„• β†’ (β„• β†’ β„•) β†’ β„• β†’ Prop) (P_def : βˆ€ x g p, P x g p ↔ if p = 0 then (βˆ€ q > 0, Β¬ IsPeriodicFrom x g q) else IsLeast {q | 0 < q ∧ IsPeriodicFrom x g q} p) : βˆƒ g : β„• β†’ β„•, (βˆ€α΅‰ (k > 0) (a : Fin k β†’ β„•) (ha : Injective a), f (βˆ‘ i, 5 ^ (a i)) = g (βˆ‘ i, a i)) ∧ P 1 g putnam_1984_a6_solution := sorry
d93bff612e25223c
putnam_2011_a6
theorem putnam_2011_a6 (G : Type*) [CommGroup G] [Fintype G] (n : β„•) (gset : Set G) (k : β„•) (mgprob : β„• β†’ G β†’ ℝ) (hmgprob : mgprob = (fun (m : β„•) (x : G) => ({f : Fin m β†’ gset | (∏ i : Fin m, (f i).1) = x}.ncard : ℝ) / k ^ m)) (hn : n = (Fintype.elems : Finset G).card) (hk : gset.encard = k) (hgsetprop : k < n) (hgset1 : 1 ∈ gset) (hgsetgen : Subgroup.closure gset = ⊀) : βˆƒ b ∈ Set.Ioo (0 : ℝ) 1, βˆƒ C > 0, Tendsto (fun m : β„• => (1 / b ^ (2 * m)) * (βˆ‘ x : G, (mgprob m x - 1 / n) ^ 2)) atTop (𝓝 C) := sorry
1f0bf8b6abf4487f
putnam_2023_b2
abbrev putnam_2023_b2_solution : β„• := sorry -- 3 /-- For each positive integer $n$, let $k(n)$ be the number of ones in the binary representation of $2023 * n$. What is the minimum value of $k(n)$? -/ theorem putnam_2023_b2 : sInf {(digits 2 (2023*n)).sum | n > 0} = putnam_2023_b2_solution := sorry
2a5047b969278943