 Every algebraic extension "F"/"K" admits a normal closure "L", which is an extension field of "F" such that "L"/"K" is normal and which is minimal with this property.An algebraic extension "L"/"K" is called separable if the minimal polynomial of every element of "L" over "K" is separable, i.e., has no repeated roots in an algebraic closure over "K".A Galois extension is a field extension that is both normal and separable.