I was impressed by the work of A. Wiles on the last Fermat's theorem, with the demonstration of the Taniyama-Shimura conjecture. On the other hand, I think it is very interesting the demonstration of the four colours theorem by means of a lot of computer's work. It seems to me that these two examples are very different forms of mathematic methodology. What would be the future of "demonstration" by computer? Would it be a true demonstration? I am thinking in the potential power of genetic algorithms in this respect.