Creates the unimodal bipartite projects of
existing-graph with vertexes for each vertex of existing graph whosevertex-classifier is eq to vertex-class and where an edge existing
between two vertexes of the graph if and only if they are connected to
a shared vertex in the existing-graph.
| project-bipartite-graph < basic-graph > < t > < t > < t > |
| project-bipartite-graph < symbol > < t > < t > < t > |