abstract = "When Genetic Programming is used to evolve arithmetic
functions it often operates by composing them from a
fixed collection of elementary operators and applying
them to parameters or certain primitive constants. This
limits the expressiveness of the programs that can be
evolved. It is possible to extend the expressiveness of
such an approach significantly without leaving the
comfort of terminating programs by including primitive
recursion as a control operation.The technique used
here was gene expression programming [2], a variation
of grammatical evolution [8]. Grammatical evolution
avoids the problem of program bloat; its separation of
genotype (string of symbols) and phenotype (expression
tree) permits to optimise the generated programs
without interfering with the evolutionary process.",
notes = "GECCO-2006 A joint meeting of the fifteenth
international conference on genetic algorithms
(ICGA-2006) and the eleventh annual genetic programming
conference (GP-2006).