====== Combining  ======

Node patterns, combined with path patterns, define a connected pattern graph. The pattern graph may additionally:
  * Combine several path patterns without node pattern.
  * Use unconnected part with the separator comma ('','').
  * Include boolean valued expression as condition.

===== Combined path pattern =====

If several path pattern are used between two node pattern, it is implicitly using any type of node. E.g. ''Node > > +> Node'' finds nodes connected with a path of two successor edges, and one branch edge.

===== Unconnected part =====

Unconnected pattern are defined with a comma. E.g. ''n1:Node, n2:Node'' find all pairs of nodes, without imposing any relation between the two. The two nodes will be separately matched, i.e. n1 != n2.

===== Conditions =====

Additional conditions can be used as boolean-valued expression. These expression must be declared between parentheses (''('' and '')''). E.g. ''n:Sphere, (n.diameter == 5) ''.