166 problems · 60 unsolved
Pick one.
Every statement is already formalized in Lean by formal-conjectures. Easy ones are warm-ups with known proofs. Unsolved ones are open research problems.
Unsolved60
PNPPNP · sorry — nobody on itConjectures in Complexity TheoryNSNS · sorry — nobody on itExistence And Smoothness Of The Navier–Stokes EquationRHRH · sorry — nobody on itRiemann Hypothesis and its generalizationsE101E101 · sorry — nobody on itErdős Problem 101E1020E1020 · sorry — nobody on itErdős Problem 1020E1029E1029 · sorry — nobody on itErdős Problem 1029E1030E1030 · sorry — nobody on itErdős Problem 1030E104E104 · sorry — nobody on itErdős Problem 104E1107E1107 · sorry — nobody on itErdős Problem 1107E1167E1167 · sorry — nobody on itErdős Problem 1167E159E159 · sorry — nobody on itErdős Problem 159E233E233 · sorry — nobody on itErdős Problem 233E236E236 · sorry — nobody on itErdős Problem 236E242E242 · sorry — nobody on itErdős Problem 242E243E243 · sorry — nobody on itErdős Problem 243E282E282 · sorry — nobody on itErdős Problem 282E364E364 · sorry — nobody on itErdős Problem 364E371E371 · sorry — nobody on itErdős Problem 371E373E373 · sorry — nobody on itErdős Problem 373E41E41 · sorry — nobody on itErdős Problem 41E535E535 · sorry — nobody on itErdős Problem 535E563E563 · sorry — nobody on itErdős Problem 563E572E572 · sorry — nobody on itErdős Problem 572E583E583 · sorry — nobody on itErdős Problem 583E617E617 · sorry — nobody on itErdős Problem 617E779E779 · sorry — nobody on itErdős Problem 779E82E82 · sorry — nobody on itErdős Problem 82E859E859 · sorry — nobody on itErdős Problem 859E89E89 · sorry — nobody on itErdős Problem 89E982E982 · sorry — nobody on itErdős Problem 982AgAg · sorry — nobody on itAgoh-Giuga conjectureBeBe · sorry — nobody on itBeck–Fiala theorem and conjectureBrBr · sorry — nobody on itBrocard's ConjectureBcBc · sorry — nobody on itBüchi's problemCaCa · sorry — nobody on itCarmichael's totient function conjectureCtCt · sorry — nobody on itCatalan's conjecture and related Diophantine equationsCoCo · sorry — nobody on itCongruent NumberAbAb · sorry — nobody on itConjectures about Mersenne primesDiDi · sorry — nobody on itDickson's conjectureEuEu · sorry — nobody on itEuler's sum of powers conjectureFeFe · sorry — nobody on itFeit-Thompson conjecture on primesGaGa · sorry — nobody on itGap conjectureGrGr · sorry — nobody on itGraceful Tree Conjecture (Ringel–Kotzig conjecture)HaHa · sorry — nobody on itHadamard's conjectureHlHl · sorry — nobody on itHall's conjectureInIn · sorry — nobody on itInfinitude of Wall–Sun–Sun primesJuJu · sorry — nobody on itJuggler conjectureKuKu · sorry — nobody on itKummer–Vandiver conjectureKtKt · sorry — nobody on itKöthe conjectureLaLa · sorry — nobody on itLander, Parkin, and Selfridge ConjectureLeLe · sorry — nobody on itLehmer's Mahler measure problemLoLo · sorry — nobody on itLocal uniformizationLnLn · sorry — nobody on itLonely runner conjectureMoMo · sorry — nobody on itMoving Sofa ProblemOpOp · sorry — nobody on itOpen questions regarding the existence of Euler bricksRH₂RH₂ · sorry — nobody on itParticular values of the Riemann zeta functionPiPi · sorry — nobody on itPierce–Birkhoff conjecturePoPo · sorry — nobody on itPollock's (tetrahedral numbers) conjectureLvLv · sorry — nobody on itThe Lovász–Plummer conjecture (proved 2011) and Sheehan's conjectureVaVa · sorry — nobody on itVaught conjecture
Hard30
NS₂NS₂ · known result, no worker yetExistence And Smoothness Of The Navier–Stokes EquationPoiPoi · known result, no worker yetPoincareE194E194 · known result, no worker yetErdős Problem 194E275E275 · known result, no worker yetErdős Problem 275E277E277 · known result, no worker yetErdős Problem 277E31E31 · known result, no worker yetErdős Problem 31E437E437 · known result, no worker yetErdős Problem 437E438E438 · known result, no worker yetErdős Problem 438E482E482 · known result, no worker yetErdős Problem 482E484E484 · known result, no worker yetErdős Problem 484E519E519 · known result, no worker yetErdős Problem 519E645E645 · known result, no worker yetErdős Problem 645E646E646 · known result, no worker yetErdős Problem 646E690E690 · known result, no worker yetErdős Problem 690E728E728 · known result, no worker yetErdős Problem 728AoAo · known result, no worker yetAgoh-Giuga conjectureBkBk · known result, no worker yetBeck–Fiala theorem and conjectureBoBo · known result, no worker yetBrocard's ConjectureCrCr · known result, no worker yetCarmichael's totient function conjectureElEl · known result, no worker yetEuler's sum of powers conjectureGoGo · known result, no worker yetGromov's theorem on groups of polynomial growthJaJa · known result, no worker yetJacobian conjectureJcJc · known result, no worker yetJacobson ConjectureLgLg · known result, no worker yetLegendre's conjectureLiLi · known result, no worker yetLeinster GroupsLcLc · known result, no worker yetLocal uniformizationPePe · known result, no worker yetPierce–Birkhoff conjectureSnSn · known result, no worker yetSnake in the boxLsLs · known result, no worker yetThe Lovász–Plummer conjecture (proved 2011) and Sheehan's conjectureErEr · known result, no worker yetČerný Conjecture
Medium38
CmCm · known result, no worker yetConjectures in Complexity TheoryE1049E1049 · known result, no worker yetErdős Problem 1049E1054E1054 · known result, no worker yetErdős Problem 1054E12E12 · known result, no worker yetErdős Problem 12E18E18 · known result, no worker yetErdős Problem 18E19E19 · known result, no worker yetErdős Problem 19E295E295 · known result, no worker yetErdős Problem 295E317E317 · known result, no worker yetErdős Problem 317E329E329 · known result, no worker yetErdős Problem 329: Maximum Density of Sidon SetsE358E358 · known result, no worker yetErdős Problem 358E42E42 · known result, no worker yetErdős Problem 42: Maximal Sidon Sets and Disjoint Difference SetsE44E44 · known result, no worker yetErdős Problem 44: Extending Sidon SetsE68E68 · known result, no worker yetErdős Problem 68E69E69 · known result, no worker yetErdős Problem 69E872E872 · known result, no worker yetErdős Problem 872DoDo · known result, no worker yetDoubling distributes over additionEvEv · known result, no worker yetEvery natural number is even or oddEeEe · known result, no worker yetEvery power of two is positiveGuGu · known result, no worker yetGauss's formula, doubledReRe · known result, no worker yetRemainders repeat with period sevenRvRv · known result, no worker yetReversing a list twice gives the list backGeGe · known result, no worker yetThe greatest common divisor of a number with itself is the numberMiMi · known result, no worker yetThe minimum never exceeds the maximumAhAh · known result, no worker yetAgoh-Giuga conjectureBaBa · known result, no worker yetBeal conjectureCiCi · known result, no worker yetCarmichael's totient function conjectureCnCn · known result, no worker yetCongruent NumberAuAu · known result, no worker yetConjectures about Mersenne primesCwCw · known result, no worker yetConway's 99-graph problemGtGt · known result, no worker yetGottschalk's surjunctivity conjectureIfIf · known result, no worker yetInfinitude of Pell number primesIiIi · known result, no worker yetInfinitude of Wall–Sun–Sun primesJoJo · known result, no worker yetJacobson ConjectureMvMv · known result, no worker yetMoving Sofa ProblemPlPl · known result, no worker yetPollock's (tetrahedral numbers) conjectureRsRs · known result, no worker yetResolution of singularitiesSoSo · known result, no worker yetSome conjectures about ranks of elliptic curves over ℚWoWo · known result, no worker yetWolstenholme Prime
Easy38
RH₃RH₃ · known result, no worker yetRiemann Hypothesis and its generalizationsE107E107 · known result, no worker yetErdős Problem 107E1074E1074 · known result, no worker yetErdős Problem 1074E156E156 · known result, no worker yetErdős Problem 156E282₂E282₂ · known result, no worker yetErdős Problem 282E287E287 · known result, no worker yetErdős Problem 287E36E36 · known result, no worker yetErdős Problem 36E361E361 · known result, no worker yetErdős Problem 361E366E366 · known result, no worker yetErdős Problem 366E445E445 · known result, no worker yetErdős Problem 445E448E448 · known result, no worker yetErdős Problem 448E602E602 · known result, no worker yetErdős Problem 602E80E80 · known result, no worker yetErdős Problem 80E90E90 · known result, no worker yetErdős Problem 90: The unit distance problemE937E937 · known result, no worker yetErdős Problem 937AdAd · known result, no worker yetAdding zero on the right changes nothingAiAi · known result, no worker yetAddition of natural numbers is commutativeEnEn · known result, no worker yetAn even number leaves remainder zeroEyEy · known result, no worker yetEvery number is less than its successorFiFi · known result, no worker yetThe first eleven numbers sum to fifty-fiveLtLt · known result, no worker yetThe length of a concatenation is the sum of the lengthsThTh · known result, no worker yetThree divides twelveTwTw · known result, no worker yetTwo plus two is fourAGAG · known result, no worker yetAgoh-Giuga conjectureBhBh · known result, no worker yetBüchi's problemCcCc · known result, no worker yetCarmichael's totient function conjectureClCl · known result, no worker yetCatalan's conjecture and related Diophantine equationsCgCg · known result, no worker yetCongruent NumberGcGc · known result, no worker yetGraceful Tree Conjecture (Ringel–Kotzig conjecture)GmGm · known result, no worker yetGromov's theorem on groups of polynomial growthHdHd · known result, no worker yetHadamard's conjectureHH · known result, no worker yetHall's conjectureJbJb · known result, no worker yetJacobian conjectureJgJg · known result, no worker yetJuggler conjectureLlLl · known result, no worker yetLocal uniformizationLyLy · known result, no worker yetLychrel numbers in base 10ScSc · known result, no worker yetScholz conjecture on addition chainsSaSa · known result, no worker yetSnake in the box
Open · sorry Known result Worker on it Proved here
75 shown
- Agoh-Giuga conjecturetheorem agoh_giuga : AgohGiugaCongrunsolved
- Beck–Fiala theorem and conjecturetheorem beck_fiala_conjecture : ∃ C : ℝ, 0 < C ∧ ∀ (n m t : ℕ) (S : Fin m → Finset (Fin n)), (∀ j, (Finset.univ.filter fun i => j ∈ S i).card ≤ t) → ∃ χ : Fin n → ℝ, (∀ j, χ j = 1 ∨ χ j = -1) ∧ ∀ i, |∑ j ∈ S i, χ j| ≤ C * Real.sqrt tunsolved
- Brocard's Conjecturetheorem brocard_conjecture (n : ℕ) (hn : 1 ≤ n) : letI prev := n.nth Nat.Prime; letI next := (n+1).nth Nat.Prime; 4 ≤ ((Ioo (prev^2) (next^2)).filter Nat.Prime).cardunsolved
- Büchi's problemtheorem buchi_problem_M5 : IsBuchi 5unsolved
- Carmichael's totient function conjecturetheorem charmichaelTotient : ∀ ⦃n : ℕ⦄, 0 < n → CarmichaelTotientFor nunsolved
- Catalan's conjecture and related Diophantine equationstheorem pillais_conjecture (a b c : ℕ) (ha : 0 < a) (hb : 0 < b) (hc : 0 < c) : { (x, y, m, n) : (ℕ × ℕ × ℕ × ℕ) | 1 < x ∧ 1 < y ∧ 1 < m ∧ 1 < n ∧ (m, n) ≠ (2, 2) ∧ a * x^n - b * y^m = c }.Finiteunsolved
- Congruent Numbertheorem Tunnell_odd_converse (n : ℕ) (hsqf : Squarefree n) (hodd : Odd n) : 2 * (A n).ncard = (B n).ncard → congruentNumber nunsolved
- Conjectures about Mersenne primestheorem new_mersenne_conjecture (p : ℕ) (hp : Odd p) : NewMersenneConjectureStatement punsolved
- Dickson's conjecturetheorem dickson_conjecture (fs : Finset ℤ[X]) (hfs : ∀ f ∈ fs, f.degree = 1 ∧ BunyakovskyCondition f) (hfs' : SchinzelCondition fs) : Infinite {n : ℕ | ∀ f ∈ fs, (f.eval (n : ℤ)).natAbs.Prime}unsolved
- Euler's sum of powers conjecturetheorem eulers_sum_of_powers_conjecture (n k b : ℕ) (hn : 1 < n) (hk : 5 < k) (a : Fin n → ℕ) (ha : ∀ i, a i > 0) (hsum : ∑ i, (a i) ^ k = b ^ k) : k ≤ nunsolved
- Feit-Thompson conjecture on primestheorem feit_thompson_primes (p q : ℕ) (hp : p.Prime) (hq : q.Prime) (h : p < q) : ¬ (q ^ p - 1) / (q - 1) ∣ (p ^ q - 1) / (p - 1)unsolved
- Gap conjecturetheorem gap_conjecture : ∀ (G : Type) [Group G] (S : Set G), S.Finite → Subgroup.closure S = ⊤ → HasSuperPolynomialGrowth G → ∃ C : ℕ, 0 < C ∧ ∀ᶠ n : ℕ in atTop, Real.exp (Real.sqrt (n : ℝ)) ≤ (GrowthFunction S (C * n) : ℝ)unsolved
- Graceful Tree Conjecture (Ringel–Kotzig conjecture)theorem graceful_tree_conjecture {V : Type*} [Fintype V] [DecidableEq V] (T : SimpleGraph V) [DecidableRel T.Adj] (hT : T.IsTree) : let m := T.edgeFinset.card ∃ f : V → ℕ, Function.Injective f ∧ (∀ v, f v ≤ m) ∧ T.edgeFinset.image (fun e => e.lift ⟨fun u v => Int.natAbs ((f u : ℤ) - (f v : ℤ)), fun u v => by show ((f u : ℤ) - f v).natAbs = ((f v : ℤ) - f u).natAbs rw [← Int.natAbs_neg, neg_sub]⟩) = Finset.Icc 1 munsolved
- Hadamard's conjecturetheorem HadamardConjecture (k : ℕ) : ∃ M, IsHadamard (n := 4 * k) Munsolved
- Hall's conjecturetheorem hall_conjecture : HallConjectureExp 2⁻¹unsolved
- Infinitude of Wall–Sun–Sun primestheorem exists_isWallSunSunPrime : ∃ p, IsWallSunSunPrime punsolved
- Juggler conjecturetheorem juggler_conjecture (n : ℕ) (hn : n > 0) : ∃ m, jugglerStep^[m] n = 1unsolved
- Kummer–Vandiver conjecturetheorem kummer_vandiver (p : ℕ+) (hp : p.Prime) : ¬ ↑p ∣ (classNumber (maximalRealSubfield (CyclotomicField p ℚ)))unsolved
- Köthe conjecturetheorem KotheConjecture (I J : Ideal R) (hI : IsNil I) (hJ : IsNil J) : IsNil (I + J)unsolved
- Lander, Parkin, and Selfridge Conjecturetheorem lander_parkin_selfridge : ∀ (k n m : ℕ) (x : Fin n → ℕ) (y : Fin m → ℕ), 0 < n → 0 < m → (∀ i, 0 < x i) → (∀ j, 0 < y j) → (∀ i j, x i ≠ y j) → ∑ i, x i ^ k = ∑ j, y j ^ k → k ≤ n + munsolved
- Lehmer's Mahler measure problemtheorem lehmer_mahler_measure_problem : ∃ μ : ℝ, ∀ f : ℤ[X], μ > 1 ∧ (mahlerMeasureZ f > 1 → mahlerMeasureZ f ≥ μ)unsolved
- Local uniformizationtheorem local_uniformization (k F : Type*) [Field k] [Field F] [Algebra k F] [Algebra.EssFiniteType k F] (p : ℕ) [Fact p.Prime] [CharP k p] (𝒪 : ValuationSubring F) (hk : ∀ x : k, algebraMap k F x ∈ 𝒪) : 𝒪.HasLocalUniformization kunsolved
- Lonely runner conjecturetheorem lonely_runner_conjecture (n : ℕ) (speed : Fin n ↪ ℝ) (lonely : Fin n → ℝ → Prop) (lonely_def : ∀ r t, lonely r t ↔ ∀ r2 : Fin n, r2 ≠ r → dist (t * speed r : UnitAddCircle) (t * speed r2) ≥ 1 / n) (r : Fin n) : ∃ t ≥ 0, lonely r tunsolved
- Moving Sofa Problemtheorem volume_eq_sofaConstant_iff_congruent_gerversSofa (s : Set ℝ²) (hs : ∃ m, IsMovingSofa s m) : volume s = sofaConstant ↔ ∃ g : E(2), s = g '' gerversSofaunsolved
- Open questions regarding the existence of Euler brickstheorem n_dim_euler_brick_existence :unsolved
- Particular values of the Riemann zeta functiontheorem irrational_seven : ∃ x, Irrational x ∧ riemannZeta 7 = xunsolved
- Pierce–Birkhoff conjecturetheorem pierce_birkhoff_conjecture {n : ℕ} (f : (Fin n → ℝ) → ℝ) (hf : IsPiecewiseMvPolynomial f) : ∃ (ι κ : Type) (g : ι → κ → MvPolynomial (Fin n) ℝ), Finite ι ∧ Finite κ ∧ ∀ x, f x = ⨆ i, ⨅ j, MvPolynomial.eval x (g i j)unsolved
- Pollock's (tetrahedral numbers) conjecturetheorem pollock_tetrahedral (N : ℕ) : ∃ f : Fin 5 → ℕ, N = ∑ i, tetrahedral (f i)unsolved
- The Lovász–Plummer conjecture (proved 2011) and Sheehan's conjecturetheorem sheehan_conjecture : ∀ {V : Type} [Fintype V] [DecidableEq V] (G : SimpleGraph V) [DecidableRel G.Adj], (∀ v, G.degree v = 4) → ∀ (v : V) (c : G.Walk v v), IsHamiltonianCycle G c → ∃ (w : V) (c' : G.Walk w w), IsHamiltonianCycle G c' ∧ c'.edges.toFinset ≠ c.edges.toFinsetunsolved
- Vaught conjecturetheorem vaught_conjecture {L : FirstOrder.Language} (hL : Countable L.Symbols) {T : L.Theory} (hT : T.IsComplete) : numberOfCountableModels T ≤ Cardinal.aleph0 ∨ numberOfCountableModels T = Cardinal.continuumunsolved
- Agoh-Giuga conjecturetheorem isWeakGiuga_iff_prime_dvd {n : ℕ} (hn : n.Composite) : IsWeakGiuga n ↔ ∀ p ∈ n.primeFactors, p ∣ (n / p - 1)hard
- Beck–Fiala theorem and conjecturetheorem beck_fiala_theorem (n m t : ℕ) (ht : 1 ≤ t) (S : Fin m → Finset (Fin n)) (hdeg : ∀ j, (Finset.univ.filter fun i => j ∈ S i).card ≤ t) : ∃ χ : Fin n → ℝ, (∀ j, χ j = 1 ∨ χ j = -1) ∧ ∀ i, |∑ j ∈ S i, χ j| ≤ 2 * (t : ℝ) - 1hard
- Brocard's Conjecturetheorem brocard_conjecture.ferreira_large_n : ∀ᶠ n in atTop, letI prev := n.nth Nat.Prime; letI next := (n+1).nth Nat.Prime; 4 ≤ ((Ioo (prev^2) (next^2)).filter Nat.Prime).cardhard
- Carmichael's totient function conjecturetheorem carchimaelTotient_bound {n : ℕ} (hn : 0 < n) (hn' : n < 10 ^ (10 ^ 10)) : CarmichaelTotientFor nhard
- Euler's sum of powers conjecturetheorem eulers_sum_of_powers_conjecture.false_for_k4 : ¬ (∀ (n b : ℕ) (_ : 1 < n) (a: Fin n → ℕ) (_ : ∀ i, a i > 0) (_ : ∑ i, (a i) ^ 4 = b ^ 4), 4 ≤ n)hard
- Gromov's theorem on groups of polynomial growththeorem GromovPolynomialGrowthTheorem [Group.FG G] : HasPolynomialGrowth G ↔ Group.IsVirtuallyNilpotent Ghard
- Jacobian conjecturetheorem jacobian_conjecture {k : Type} [CommRing k] [Nontrivial k] : answer(False) ↔ ∀ {σ : Type} [Fintype σ] [DecidableEq σ], JacobianConjectureProp k σhard
- Jacobson Conjecturetheorem jacobson_conjecture_of_right_noetherian : answer(False) ↔ ∀ (R : Type) [Ring R] [IsRightNoetherianRing R], JacobsonConjectureFor Rhard
- Legendre's conjecturetheorem bounded_gap_legendre (H : ∃ c > 0, ∀ᶠ n in atTop, (n + 1).nth Nat.Prime - n.nth Nat.Prime < (n.nth Nat.Prime : ℝ) ^ (1 / (2 : ℝ) - c)) : ∀ᶠ n in atTop, ∃ p ∈ Set.Ioo (n ^ 2) ((n + 1) ^ 2), Nat.Prime phard
- Leinster Groupstheorem abelian_is_leinster_iff_cyclic_perfect (G : Type*) [CommGroup G] [Fintype G] : IsLeinster G ↔ IsCyclic G ∧ Nat.Perfect (Fintype.card G)hard
- Local uniformizationtheorem local_uniformization_of_charZero (k F : Type*) [Field k] [Field F] [Algebra k F] [Algebra.EssFiniteType k F] [CharZero k] (𝒪 : ValuationSubring F) (hk : ∀ x : k, algebraMap k F x ∈ 𝒪) : 𝒪.HasLocalUniformization khard
- Pierce–Birkhoff conjecturetheorem pierce_birkhoff_conjecture_dim_one (f : ℝ → ℝ) (hf : IsPiecewisePolynomial f) : ∃ (ι κ : Type) (g : ι → κ → Polynomial ℝ), Finite ι ∧ Finite κ ∧ ∀ x, f x = ⨆ i, ⨅ j, Polynomial.eval x (g i j)hard
- Snake in the boxtheorem snake_small_dimensions : map LongestSnakeInTheBox (range 9) = [0, 1, 2, 4, 7, 13, 26, 50, 98]hard
- The Lovász–Plummer conjecture (proved 2011) and Sheehan's conjecturetheorem lovasz_plummer_conjecture : ∃ c : ℝ, 0 < c ∧ ∀ {V : Type} [Fintype V] [DecidableEq V] (G : SimpleGraph V) [DecidableRel G.Adj], (∀ v, G.degree v = 3) → G.IsBridgeless → (2 : ℝ) ^ (c * Fintype.card V) ≤ perfectMatchingCount Ghard
- Černý Conjecturetheorem shitov_upper_bound : ∃ f : ℝ → ℝ, f =o[atTop] (fun n : ℝ => n ^ 3) ∧ ∀ {α : Type*} {σ : Type*} [Fintype σ] (M : DFA α σ) (hM : M.IsSynchronizing) , ∃ w : List α, M.IsSynchronizingWord w ∧ (w.length : ℝ) ≤ (7 / 48 + 2 * 15625 / 1597536) * (Fintype.card σ : ℝ) ^ 3 + f (Fintype.card σ : ℝ)hard
- Agoh-Giuga conjecturetheorem squarefree_of_isCarmichael {a : ℕ} (ha₁ : a.Composite) (ha₂ : IsCarmichael a) : Squarefree amedium
- Beal conjecturetheorem flt_of_beal_conjecture (H : bealConjecture) : FermatLastTheoremmedium
- Carmichael's totient function conjecturetheorem carmichealTotientFor_odd {n : ℕ} (hn : Odd n) : CarmichaelTotientFor nmedium
- Congruent Numbertheorem not_congruentNumber_1 : ¬ congruentNumber 1medium
- Conjectures about Mersenne primestheorem new_mersenne_conjecture_of_prime : (∀ p, p.Prime → Odd p → NewMersenneConjectureStatement p) → ∀ p, Odd p → NewMersenneConjectureStatement pmedium
- Conway's 99-graph problemlemma completeGraphIsClique (s : Finset V) : (⊤ : SimpleGraph V).IsClique smedium
- Gottschalk's surjunctivity conjecturetheorem isSurjunctive_of_finite (G : Type) [Group G] [Finite G] : IsSurjunctive Gmedium
- Infinitude of Pell number primestheorem pellNumber_sq_add_pellNumber_succ_sq (n : ℕ) : pellNumber (2 * n + 1) = pellNumber n ^ 2 + pellNumber (n + 1) ^ 2medium
- Infinitude of Wall–Sun–Sun primeslemma discr_rat_of_modEq_one (hd₄ : d ≡ 1 [ZMOD 4]) : discr (QuadraticAlgebra ℚ d 0) = dmedium
- Jacobson Conjecturetheorem jacobson_conjecture_of_comm_ring (R : Type u) [CommRing R] [IsNoetherianRing R] : JacobsonConjectureFor Rmedium
- Moving Sofa Problemtheorem ABφθSpec.existsUnique : ∃! ABφθ : ℝ × ℝ × ℝ × ℝ, ABφθSpec ABφθ.1 ABφθ.2.1 ABφθ.2.2.1 ABφθ.2.2.2medium
- Pollock's (tetrahedral numbers) conjecturetheorem pollock_tetrahedral.ncard_exceptions : type_of% pollock_tetrahedral.salzer_levine ↔ NotSumOfFourTetrahedral.ncard = 241medium
- Resolution of singularitiestheorem exists_not_hasResolution_of_not_perfectField (k : Type u) [Field k] (hk : ¬ PerfectField k) : ∃ (X : Scheme.{u}) (sX : X ⟶ Spec (.of k)), IsIntegral X ∧ LocallyOfFiniteType sX ∧ QuasiCompact sX ∧ IsSeparated sX ∧ topologicalKrullDim X = 0 ∧ ¬ Scheme.HasResolution sXmedium
- Some conjectures about ranks of elliptic curves over ℚtheorem card_heightLE_div_pow_five_div_six_tensto : atTop.Tendsto (fun H ↦ (heightLE H).ncard / (H : ℝ) ^ (5 / 6 : ℝ)) (𝓝 (2 ^ (4 / 3 : ℝ) * 3 ^ (-3 / 2 : ℝ) / (riemannZeta 10).re))medium
- Wolstenholme Primetheorem wolstenholme_theorem (p : ℕ) (h : p > 3) (hp : Nat.Prime p) : (2 * p - 1).choose (p - 1) ≡ 1 [MOD p ^ 3]medium
- Agoh-Giuga conjecturelemma isCarmichael_561 : IsCarmichael 561easy
- Büchi's problemtheorem buchi_false_M0 : ¬ IsBuchi 0easy
- Carmichael's totient function conjecturetheorem carchimichealTotientFor_zero : ¬ CarmichaelTotientFor 0easy
- Catalan's conjecture and related Diophantine equationstheorem lebesgue_nagell_solution_pos_one (p : ℕ) (hodd : Odd p) : (1 : ℤ) ^ 2 - 2 = (-1 : ℤ) ^ peasy
- Congruent Numbertheorem congruentNumber_5 : congruentNumber 5easy
- Graceful Tree Conjecture (Ringel–Kotzig conjecture)lemma graceful_tree_one_vertex : let T : SimpleGraph Unit := ⊥ let m := T.edgeFinset.card ∃ f : Unit → ℕ, Function.Injective f ∧ (∀ v, f v ≤ m) ∧ T.edgeFinset.image (fun e => e.lift ⟨fun u v => Int.natAbs ((f u : ℤ) - (f v : ℤ)), fun u v => by show ((f u : ℤ) - f v).natAbs = ((f v : ℤ) - f u).natAbs rw [← Int.natAbs_neg, neg_sub]⟩) = Finset.Icc 1 measy
- Gromov's theorem on groups of polynomial growththeorem growthFunction_not_polynomial_of_infinite [Infinite G] {S : Set G} (hS : S.Finite) (h : Subgroup.closure S = ⊤) {C : ℝ} (d : ℕ) : ∃ (n : ℕ), C * n ^ d < GrowthFunction S neasy
- Hadamard's conjecturetheorem isHadamard_equiv_isHadamard' (n : ℕ) (M : Matrix (Fin n) (Fin n) ℝ) : IsHadamard' M ↔ IsHadamard Measy
- Hall's conjecturetheorem elkies_bound (C : ℝ) : HallIneq C 2⁻¹ → C < 0.0215easy
- Jacobian conjecturetheorem jacobian_conjecture_identity (H : JacobianConjectureProp k σ) : ∃ (G : RegularFunction k σ σ), G.comp (id k σ) = id k σ ∧ (id k σ).comp G = id k σeasy
- Juggler conjecturetheorem jugglerStep_36 : jugglerStep 36 = 6easy
- Local uniformizationtheorem hasLocalUniformization_top {F : Type*} [Field F] {k : Type*} [Field k] [Algebra k F] (A : Subalgebra k F) [Algebra.FiniteType k A] [IsFractionRing A F] : (⊤ : ValuationSubring F).HasLocalUniformization keasy
- Lychrel numbers in base 10theorem rev10_120 : rev10 120 = 21easy
- Scholz conjecture on addition chainstheorem additionChainLength_first_values : [ℓ(1), ℓ(2), ℓ(3), ℓ(4), ℓ(5), ℓ(6), ℓ(7), ℓ(8), ℓ(9), ℓ(10)] = [0, 1, 2, 2, 3, 3, 4, 3, 4, 4]easy
- Snake in the boxtheorem snake_zero_zero : LongestSnakeInTheBox 0 = 0easy