EVOLP definition:
J. J. Alferes, A. Brogi, J. A. Leite and L. M. Pereira.
Evolving Logic Programs. In S. Flesca,
S. Greco, N. Leone, G. Ianni (eds.), Proceedings of
the 8th European Conference on Logics in Artificial
Intelligence (JELIA'02), pages 50-61, Spriger-Verlag,
LNCS 2424, 2002. © Springer-Verlag.