Re: [math-fun] Combinatorial Designs, maybe

P.S. Um, it seems clear that the collections of subsets R, C are maximal w.r.t. the symmetry I asked about, since any permutations P_r, P_c, and P_rc determines uniquely a permutation P of the set S. _____________________________________________________________________ "It don't mean a thing if it ain't got that certain je ne sais quoi." --Peter Schickele