Graphs

A directed graph is a term graph(V,E) where V is a list of vertices and E is a list of edges (none necessarily sorted). Edges are pairs of vertices which are directed, i.e., (a,b) represents a->b. Two vertices a and b are equal only if a==b.

Usage:dgraph(Graph)

Graph is a directed graph.

A labeled directed graph is a directed graph where edges are triples of the form (a,l,b) where l is the label of the edge (a,b).

Usage:dlgraph(Graph)

Graph is a directed labeled graph.

Usage:dgraph_to_ugraph(Graph,UGraph)

Converts Graph to UGraph.

• The following properties should hold at call time:
  (term_typing:nonvar/1)Graph is currently a term which is not a free variable.
  (term_typing:var/1)UGraph is a free variable.
  (graphs:dgraph/1)Graph is a directed graph.
  (term_typing:var/1)UGraph is a free variable.
• The following properties should hold upon exit:
  (graphs:dgraph/1)Graph is a directed graph.
  (ugraphs:ugraph/1)UGraph is an ugraph.

Usage:dlgraph_to_lgraph(Graph,LGraph)

Converts Edges to LGraph.

• The following properties should hold at call time:
  (term_typing:nonvar/1)Graph is currently a term which is not a free variable.
  (term_typing:var/1)LGraph is a free variable.
  (graphs:dlgraph/1)Graph is a directed labeled graph.
  (term_typing:var/1)LGraph is a free variable.
• The following properties should hold upon exit:
  (graphs:dlgraph/1)Graph is a directed labeled graph.
  (lgraphs:lgraph/2)LGraph is a labeled graph of term terms.

Usage:edges_to_ugraph(Edges,UGraph)

Converts Graph to UGraph.

• The following properties should hold at call time:
  (term_typing:nonvar/1)Edges is currently a term which is not a free variable.
  (term_typing:var/1)UGraph is a free variable.
  (basic_props:list/2)Edges is a list of pairs.
  (term_typing:var/1)UGraph is a free variable.
• The following properties should hold upon exit:
  (basic_props:list/2)Edges is a list of pairs.
  (ugraphs:ugraph/1)UGraph is an ugraph.

Usage:edges_to_lgraph(Edges,LGraph)

Converts Edges to LGraph.

• The following properties should hold at call time:
  (term_typing:nonvar/1)Edges is currently a term which is not a free variable.
  (term_typing:var/1)LGraph is a free variable.
  (basic_props:list/2)Edges is a list of triples.
  (term_typing:var/1)LGraph is a free variable.
• The following properties should hold upon exit:
  (basic_props:list/2)Edges is a list of triples.
  (lgraphs:lgraph/2)LGraph is a labeled graph of term terms.

Usage:pair(P)

P is a pair (_,_).

Usage:triple(P)

P is a triple (_,_,_).