“…Graphs are attractive representations for programs as they are more compact than the more usual tree representation since subgraphs can be used more than once. CGP has been applied to a growing number of domains and problems: digital circuit design [11,12], digital filter design [8], image processing [21], artificial life [20], bio-inspired developmental models [9,14,10], evolutionary art [1], molecular docking [4] and has been adopted within new evolutionary techniques cell-based Optimization [19] and Social Programming [24]. In addition a more powerful form of CGP with the equivalent of Automatically Defined Functions is also being developed [25].…”