note Jaap Perhaps for a nice discussion, we could try to implement the "travelling salesman problem" where a salesman has to visit a bunch of points represented as (x,y) coordinates in such a way that the total distance travelled (the length of the path) is minimized (this is the fitness criterium)<br> <br> We'd need a good representation of a solution, perhaps a 2D array with a series of (x,y) coordinates. We'd also need a subroutine to calculate the length of the path. And we'd need the crossover() and mutate() functions. 298877 298877