Definition decidable_embedding sT T (f : sT -> T) :=
  forall y, decidable (exists x, y = f x).

(* Specifications: *)
Lemma rat_algebraic_decidable (C : fieldType) (QtoC : Qmorphism C) : integralRange QtoC -> decidable_embedding QtoC.
Lemma alg_integral (F : fieldType) (L : fieldExtType F) : integralRange (in_alg L).
Theorem Fundamental_Theorem_of_Algebraics : {L : closedFieldType & {conj : {rmorphism L -> L} | involutive conj & ~ conj =1 id}}.