English
The type Pell.Solution₁(d) is the collection of all solutions to the Pell equation x^2 − d y^2 = 1, realized as unitary elements of ℤ√d.
Русский
Тип Pell.Solution₁(d) состоит из всех решений уравнения Пелля x^2 − d y^2 = 1, реализованный как элементы unitary ℤ√d.
LaTeX
$$$\\text{Pell.Solution}_1(d) = \\text{unitary}(\\mathbb{Z}\\sqrt{d})$$$
Lean4
/-- `Pell.Solution₁ d` is the type of solutions to the Pell equation `x^2 - d*y^2 = 1`.
We define this in terms of elements of `ℤ√d` of norm one.
-/
def Solution₁ (d : ℤ) : Type :=
↥(unitary (ℤ√d))