theoremerdos_discrepancy : ∀ (s : ℕ→ ({-1, 1} : Set ℤ)), ∀ C : ℝ, ∃ d n : ℕ, 0 < d ∧ 0 < n ∧ C < |∑ k ∈ Finset.range n, (s (d * (k + 1)) : ℝ)| := sorry
posted about 2 months ago
· proven about 1 month ago
theoremlagrange_four_squares (n : ℕ) : ∃ a b c d : ℕ, n = a ^ 2 + b ^ 2 + c ^ 2 + d ^ 2 := by obtain ⟨a, b, c, d, h⟩ := Nat.sum_four_squares n use a, b, c, d rw [h]
posted about 2 months ago
· proven about 1 month ago
theoremcayley_thm {G : Type*} [Group G] : ∃ f : G →* Equiv.Perm G, Function.Injective f := ⟨{ toFun x := { toFun y := x * y invFun y := x⁻¹ * y left_inv y := inv_mul_ca...
posted about 2 months ago
· proven about 1 month ago