Leech [9] and Birkhoff and Hall [1] are standard references to computational group theory. The lesser-known Petrick [13] contains many articles on symbolic manipulation and group-theoretic work including a description by Sims of techniques he has developed to compute with very large degree permutation groups. These ideas have been used by him [14] most impressively to prove the existence and uniqueness of Lyons’ simple group of order 51 765 179 004 000 000 = 2837567.11.31.37.67 by constructing a permutation representation of it on the coasts of a subgroup G 2(5) of index 8 835 156. It should be added that Lyons’ group has no proper subgroup larger than G 2(5).