\manpage {ugraph} {} {Undirected Graphs}
 
\definition
An instance $G$ of the data type $ugraph$ is an undirected graph as defined
in section \ref{Graphs}. 
 
\creation U 
 
\create { }
   { creates an instance \var\ of type \name\ and initializes it to
            the empty undirected graph.  }
 
 
\operations 2 4.5 
 

see section \ref{Graphs}.

 
\implementation
see section \ref{Graphs}.

 
\manpage {UGRAPH} {vtype,etype} {Parameterized Ugraphs}
 
\definition
A parameterized undirected graph $G$ is an undirected graph whose nodes and
contain additional (user defined) data (cf. \ref{Parameterized Graphs}). Every 
node contains an element of a data type $vtype$, called the node type of $G$ 
and every edge contains an element of a data type $etype$ called the edge type 
of $G$. 
 
\create { }
   { creates an instance \var\ of type $ugraph$ and initializes it to the
    empty undirected graph. }
 
 
\operations 2 4.5
 

see section \ref{Parameterized Graphs}.

 
\implementation
see section \ref{Parameterized Graphs}.
.
 
