public BeliefSystem createBeliefSystem(BeliefSystemType type, NamedEntryPoint ep,
TruthMaintenanceSystem tms) {
switch(type) {
case SIMPLE:
return new SimpleBeliefSystem(ep, tms);
case JTMS:
return new JTMSBeliefSystem( ep, tms );
case DEFEASIBLE:
return new DefeasibleBeliefSystem( ep, tms );
}