Tmass diagram

digraph G {

artitem [shape="box"];
repository [shape="box"];
svnuser [shape="box"];
tag [shape="box"];
artist [shape="box"];
license [shape="box"];

artitem -> artist [label="0-1"];
artitem -> repository [label="1"];
artitem -> svnuser [label="0-1"];
artitem -> tag [label="*"];

repository -> license [label="*"];
repository -> svnuser [label="*"];

svnuser -> repository [label="1"];
svnuser -> artitem [label="*"];

tag -> artitem [label="*"];

artist -> artitem [label="*"];

license -> repository [label="*"];

}

digraph G {

    this -> is -> simpler

}