primal_graph (608B)
1 # Primal graph 2 3 An [undirected_graph] defined from a [DNF] or from a [hypergraph] or from a [relational_structure]. 4 5 For a [DNF]: 6 - vertices are variables 7 - edge connects two variables if they co-occur in a clause 8 9 If the [clause_width] of a [DNF] is unbounded then the primal graph contains arbitrarily large [cliques] 10 11 For a [hypergraph]: 12 - vertices are vertices 13 - edge connects two variables if they co-occur in a [hyperedge] 14 15 Likewise for [relational_structures] 16 17 Up: [graph_undirected] for [conjunctive_normal_form] 18 19 See also: [dual_graph], [incidence_graph], [primal_treewidth] 20 21 Aliases: Gaifman graph