"William James" <w_a_x_man / yahoo.com> wrote/schrieb <1170361559.491476.96660 / p10g2000cwp.googlegroups.com>: > Here's a shorter but slower way. > > def cart_prod( *args ) > args.inject([[]]){|old,lst| > lst.inject([]){|new,e| > new + old.map{|c| c.dup << e}}} > end Wow, it's really short. Maybe it's not slower at all. Did you just that? Or did you compare it actually? Regards Thomas