... n)k−1φ(k). In either case, the inequality in part 1 of the lemma holds. On the number of perfect matchings and Hamilton cycles in -regular non-bipartite graphsAlan Frieze∗Department of Mathematical ... of combinatorics 7 (2000), #R57 43 Hamilton Cycles A Hamilton cycle is the union of two perfect matchings and so h(G) ≤12m(G)2 and the upper bound in part (b) of Theorem 1 follows from the ... segment containing x, the segment containing x, and the remaining segment.Going round the cycle Ci, starting at x and ending at x, the vertices x, x,y,y,z,zmay appear in one of eight...