recurs depth search project children root user model diagram search diagram termin immedi fail match model search leav diagram predic doesn match diagram ineffici shouldn common effect current algorithm model element appear diagram includ plu addit time diagram given slightli friendli non diagram list includ element didn appear diagram go bookkeep tfm depth object node argo diagram diagram node argo diagram diagram argo diagram node pred match diagram diagram diagram place search result iter iter cg child iter node iter object child iter pred evalu child diagram pred match diagram result add child diagram add diagram depth child diagram 