% If a group has relations ab=c, bc=d, cd=h, dh=a, ha=b, it is % cyclic with order 11. The following input will not cause a proof, % but the result follows easily from examination of the lists near the % end of the output. set(auto). list(usable). x = x. f(e,x) = x. f(g(x),x) = e. f(f(x,y),z) = f(x,f(y,z)). f(a,b) = c. f(b,c) = d. f(c,d) = h. f(d,h) = a. f(h,a) = b. end_of_list.