... 70 pairs of disjoint triples, 315 pairs of triples which intersect in one point, and210 pairs of triples which intersect in two points. Since the subgraph induced by L2isregular of degree ... construction of the Hoffman-Singleton graph from the 15 points and35 lines of PG(3, 2), where edges between points and lines indicate incidence, and edgesbetween lines indicate disjointness of their ... corresponding triples, is also evident in theproof of Lemma 43. In addition, one sees again the bijection between lines of PG(3, 2) andtriples of a 7-element set, in which intersecting lines correspond...