<?xml version="1.0" encoding="UTF-8"?>

<record version="1" id="817">
 <title>vector space</title>
 <name>VectorSpace2</name>
 <created>2009-07-12 19:51:50</created>
 <modified>2009-07-12 19:51:50</modified>
 <type>Definition</type>
 <creator id="1" name="bloftin"/>
 <modifier id="1" name="bloftin"/>
 <comment>In standard LaTeX, \u and \v are accent commands (breve and caron), not mathematical vector variables. Inside math mode, make4ht/TeX4ht interprets them as accents and then produces the cascading brace errors you saw:

Missing } inserted.
Extra }, or forgotten \endgroup.</comment>
 <author id="1" name="bloftin"/>
 <classification>
	<category scheme="pacs" code="02.10.Ud"/>
	<category scheme="pacs" code="02.10.Xm"/>
	<category scheme="pacs" code="02.10.Yn"/>
	<category scheme="pacs" code="02.10.Hh"/>
 </classification>
 <related>
	<object name="HilbertSpace3"/>
 </related>
 <preamble>\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{graphicx}
\usepackage{xypic}
\renewcommand{\u}{\mathbf{u}}
\renewcommand{\v}{\mathbf{v}}
\newcommand{\w}{\mathbf{w}}
\newcommand{\0}{\mathbf{0}}</preamble>
 <content>Let $F$ be a field (or, more generally, a division ring). A \emph{vector space} $V$ over $F$ is a set with two operations, $+: V \times V \longrightarrow V$ and $\cdot: F \times V \longrightarrow V$, such that
\begin{enumerate}
\item $(\u+\v)+\w = \u+(\v+\w)$ for all $\u,\v,\w \in V$
\item $\u+\v=\v+\u$ for all $\u,\v\in V$
\item There exists an element $\0 \in V$ such that $\u+\0=\u$ for all $\u \in V$
\item For any $\u \in V$, there exists an element $\v \in V$ such that $\u+\v=\0$
\item $a \cdot (b \cdot \u) = (a \cdot b) \cdot \u$ for all $a,b \in F$ and $\u \in V$
\item $1 \cdot \u = \u$ for all $\u \in V$
\item $a \cdot (\u+\v) = (a \cdot \u) + (a \cdot \v)$ for all $a \in F$ and $\u,\v \in V$
\item $(a+b) \cdot \u = (a \cdot \u) + (b \cdot \u)$ for all $a,b \in F$ and $\u \in V$
\end{enumerate}

Equivalently, a vector space is a module $V$ over a ring $F$ which is a field (or, more generally, a division ring).

The elements of $V$ are called \emph{vectors}, and the element $\0 \in V$ is called the \emph{zero vector} of $V$.

This entry is a copy of the GNU FDL vector space article from \PMlinkexternal{PlanetMath}{http://planetmath.org/encyclopedia/VectorSpace.html}. Author of the original article: djao. History page of the original is \PMlinkexternal{here}{http://planetmath.org/?op=vbrowser&amp;from=objects&amp;id=364}</content>
</record>
