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

<record version="3" id="3831">
 <title>additive basis</title>
 <name>Basis2</name>
 <created>2002-12-26 04:12:32</created>
 <modified>2002-12-26 18:16:33</modified>
 <type>Definition</type>
 <creator id="348" name="bbukh"/>
 <author id="348" name="bbukh"/>
 <classification>
	<category scheme="msc" code="11B13"/>
 </classification>
 <defines>
	<concept>order of additive basis</concept>
 </defines>
 <synonyms>
	<synonym concept="additive basis" alias="basis"/>
 </synonyms>
 <related>
	<object name="AsymptoticBasis"/>
	<object name="SchnirlemannDensity"/>
	<object name="EssentialComponent"/>
 </related>
 <preamble>% this is the default PlanetMath preamble.  as your knowledge
% of TeX increases, you will probably want to edit this, but
% it should be fine as is for beginners.

% almost certainly you want these
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{amsfonts}

% used for TeXing text within eps files
%\usepackage{psfrag}
% need this for including graphics (\includegraphics)
%\usepackage{graphicx}
% for neatly defining theorems and propositions
%\usepackage{amsthm}
% making logically defined graphics
%\usepackage{xypic}

% there are many more packages, add them here as you need them

% define commands here</preamble>
 <content>A subset $A$ of $\mathbb{Z}$ is an \emph{(\PMlinkescapetext{additive}) basis} of \PMlinkescapetext{order} $n$ if
\begin{equation*}
nA=\mathbb{N}\cup\{0\},
\end{equation*}
where $nA$ is $n$-fold sumset of $A$. Usually it is assumed that $0$ belongs to $A$ when saying that $A$ is an additive basis.</content>
</record>
