expressible
Expressible
2007-04-14 21:26:19
2007-04-14 23:59:26
Definition
radical extension
inexpressible
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{psfrag}
\usepackage{graphicx}
\usepackage{amsthm}
\usepackage{xypic}
Let $F$ be a field and $\alpha$ be \PMlinkname{algebraic}{AlgebraicElement} over $F$. Then $\alpha$ is \emph{expressible} over $F$ if $F(\alpha)/F$ is a radical extension. On the other hand, $\alpha$ is \emph{inexpressible} over $F$ if $F(\alpha)/F$ is not a radical extension.