English
There exists a RelSeries r with length n (for infinite-dimensional r).
Русский
Существует RelSeries r длины n (при бесконечной размерности r).
LaTeX
$$$\\exists p : RelSeries\\ r, p.length = n$$$
Lean4
/-- A relation series with length `n` if the relation is infinite dimensional -/
protected noncomputable def withLength [r.InfiniteDimensional] (n : ℕ) : RelSeries r :=
(SetRel.InfiniteDimensional.exists_relSeries_with_length n).choose