English
In an algebraic setting, lift #L is bounded by the sum of cardinalities of L, R, and polynomial roots structure.
Русский
В алгебраическом контексте lifted кардинальность L ограничена суммой кардинальностей L, R и структуры корней полиномов.
LaTeX
$$$\\text{lift} \\#L \\le \\#(\\Sigma p : R[X], \\{ x : L \\mid x \\in p.aroots L \\})$$$
Lean4
/-- An integral element of an algebra is algebraic. -/
theorem isAlgebraic [Nontrivial R] {x : A} : IsIntegral R x → IsAlgebraic R x := fun ⟨p, hp, hpx⟩ =>
⟨p, hp.ne_zero, hpx⟩