Evolving Binary Decision Diagrams using Implicit Neutrality

A newalgorithm ispresented forevolving Bi- naryDecision Diagrams (BDD)thatemploys theneu- trality implicit intheBDDrepresentation. Itisshown that aneffortless neutral walkistaken; that is, aneutral walkthat requires nofitness evaluations. Experiments showthealgorithm toberobust andscalable across a rangeofn-parity problems upton = 17,andhighly ef- ficient onarangeofother functions withcompact BDD representations. Evolvability andmodularity issues are also discussed, andthesearch space isshowntobefree oflocal optima.