Using Zorn's lemma, it can be shown that every field has an algebraic closure, and that the algebraic closure of a field "K" is unique up to an isomorphism that fixes every member of "K".
It was using Zorn's lemma. It can be shown that every field has an algebraic closure, and that the algebraic closure of a field "K" is unique up to an isomorphism ". This isomorphism fixes every member of" K.