Isomorphism extension theorem


In field theory, a branch of mathematics, the isomorphism extension theorem is an important theorem regarding the extension of a field isomorphism to a larger field.

Isomorphism extension theorem

The theorem states that given any field, an algebraic extension field of and an isomorphism mapping onto a field then can be extended to an isomorphism mapping onto an algebraic extension of .
The proof of the isomorphism extension theorem depends on Zorn's lemma.