Minkowski's theorem to Zeckendorf's theorem
TheoremNiven's theorem#
Niven's theorem: The only rational values of cos that occur at rational multiples of π
are {-1, -1/2, 0, 1/2, 1}.
niven {θ : ℝ} (hθ : ∃ r, θ = ↑r * Real.pi) (hcos : ∃ q, Real.cos θ = ↑q) :
Real.cos θ ∈ {-1, -1 / 2, 0, 1 / 2, 1}
Sources
TheoremOstrowski's theorem#
Mathlib records this with 2 declarations.
Rat.AbsoluteValue.equiv_real_or_padic: Ostrowski's Theorem: every absolute value (with values in ℝ) on ℚ is equivalent
to either the standard absolute value or a p-adic absolute value for a prime p.
Rat.AbsoluteValue.equiv_real_or_padic (f : AbsoluteValue ℚ ℝ) (hf_nontriv : f.IsNontrivial) :
f ≈ Rat.AbsoluteValue.real ∨ ∃! p, ∃ (x : Fact (Nat.Prime p)), f ≈ Rat.AbsoluteValue.padic p
RatFunc.valuation_isEquiv_infty_or_adic: Ostrowski's Theorem for K(X) with K any field:
A valuation trivial on K is equivalent either to the valuation at infinity or to
the p-adic valuation for a unique maximal ideal p of K[X].
RatFunc.valuation_isEquiv_infty_or_adic.{u_1, u_2} {K : Type u_1} {Γ : Type u_2} [Field K]
[LinearOrderedCommGroupWithZero Γ] {v : Valuation (RatFunc K) Γ} [Valuation.IsTrivialOn K v]
[v.IsNontrivial] [DecidableEq (RatFunc K)] :
Xor (v.IsEquiv (RatFunc.inftyValuation K))
(∃! u, v.IsEquiv (IsDedekindDomain.HeightOneSpectrum.valuation (RatFunc K) u))
Sources
- Mathlib documentation:
Rat.AbsoluteValue.equiv_real_or_padic - Source of
Rat.AbsoluteValue.equiv_real_or_padicin Mathlib/NumberTheory/Ostrowski.lean - Mathlib documentation:
RatFunc.valuation_isEquiv_infty_or_adic - Source of
RatFunc.valuation_isEquiv_infty_or_adicin Mathlib/NumberTheory/RatFunc/Ostrowski.lean - 1000+ theorems list: Q2919401
- 1000+ theorems project: Q2919401
- Wikipedia: Ostrowski's theorem
- Wikidata: Q2919401
Uses 24
TheoremPentagonal number theorem#
Mathlib records this with 2 declarations.
PowerSeries.WithPiTopology.hasProd_one_sub_X_pow: Pentagonal number theorem for power series, expressed as an infinite product. See also
PowerSeries.WithPiTopology.hasSum_pentagonalSeries that expresses pentagonalSeries as an
infinite sum.
PowerSeries.WithPiTopology.hasProd_one_sub_X_pow.{u_1} (R : Type u_1) [CommRing R]
[TopologicalSpace R] :
HasProd (fun n => 1 - PowerSeries.X ^ (n + 1)) (PowerSeries.pentagonalSeries R)
hasProd_eulerFunction: Pentagonal number theorem for Euler function, expressed as an infinite product.
See hasSum_eulerFunction_pentagonal that expresses eulerFunction as an infinite sum.
hasProd_eulerFunction.{u_1} {R : Type u_1} [NormedCommRing R] [NormOneClass R] [CompleteSpace R]
{x : R} (hx : ‖x‖ < 1) : HasProd (fun n => 1 - x ^ (n + 1)) (eulerFunction x)
Sources
- Mathlib documentation:
PowerSeries.WithPiTopology.hasProd_one_sub_X_pow - Source of
PowerSeries.WithPiTopology.hasProd_one_sub_X_powin Mathlib/Combinatorics/Enumerative/Pentagonal/PowerSeries.lean - Mathlib documentation:
hasProd_eulerFunction - Source of
hasProd_eulerFunctionin Mathlib/Combinatorics/Enumerative/Pentagonal/EulerFunction.lean - 1000+ theorems list: Q282649
- 1000+ theorems project: Q282649
- Wikipedia: Pentagonal number theorem
- Wikidata: Q282649
Uses 12
TheoremVon Staudt–Clausen theorem#
von Staudt-Clausen theorem: For any natural number \(k\), the sum $\(B_{2k} + \sum_{p - 1 \mid 2k} \frac{1}{p}\)$ is an integer.
Bernoulli.vonStaudt_clausen (k : ℕ) :
bernoulli (2 * k) + ∑ p ∈ Finset.range (2 * k + 2) with Nat.Prime p ∧ p - 1 ∣ 2 * k, 1 / ↑p ∈
Set.range Int.cast
Sources
Uses 5
DefinitionZeckendorf's theorem#
Zeckendorf's Theorem as an equivalence between natural numbers and Zeckendorf
representations. Every natural number can be written uniquely as a sum of non-consecutive Fibonacci
numbers (if we forget about the first two terms F₀ = 0, F₁ = 1).
Nat.zeckendorfEquiv : ℕ ≃ { l // l.IsZeckendorfRep }
Sources
Uses 2
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