List<Set<Rule>> ls = new ArrayList<Set<Rule>>();
// Logical expression simplifier
Set <Rule> s = new HashSet<Rule>();
// add constant calculator rule
Rule r = new FilterConstantCalculator("FilterConstantCalculator", pc);
s.add(r);
r = new ForEachConstantCalculator("ForEachConstantCalculator", pc);
s.add(r);
ls.add(s);