abstract = "Genetic Programming (GP) is a machine learning
technique that evolves programs using natural selection
and populations dynamics. Much of the functionality of
GP depends on the representation of programs in the
population and how to handle illegal or type incoherent
expressions that arise from crossover and mutation
within a population of programs. The SKGP is a GP
system that uses graphs of combinators to represent
functions and a strong type system to inform the
crossover and mutation operations during evolution.
This produces a powerful, flexible system that has many
benefits over more conventional systems. This paper
describes the implementation of this system, gives some
examples of successful applications constructed using
the SKGP and describes future directions that may offer
a more powerful GP system capable of producing more
complex programs.",