repli set object reach receiv set take step defin given child gener result doe includ element origin set order avoid deep search program mistak path given max length consid path consist element caus predic evalu consid param cg given childgener param max maximum depth param predic predic object fulfil result listset list set reachabl argouml util child gener cg max argouml util predic predic list set kid list set list object list kid add element cg child iter predic kid transit closur cg max predic 