English
In the subalgebra context, the two-le-natDegree condition is equivalent to not belonging to the subalgebra.
Русский
В контексте подпольного алгебрного окружения условие 2 ≤ natDegree эквивалентно не принадлежности x самому S.
LaTeX
$$2 \le (\minpoly (Subtype (fun x => x ∈ S)) x).natDegree \iff x \notin S$$
Lean4
@[elab_as_elim, cases_eliminator, induction_eliminator]
theorem ind {motive : ConjRootClass K L → Prop} (h : ∀ x : L, motive (mk K x)) (c : ConjRootClass K L) : motive c :=
Quotient.ind h c