Пример #1
0
 /**
  * Computes the lowerbound from bottom-up; it will also set a suitable initial value for each
  * sig's upperbound. Precondition: sig is not a builtin sig
  */
 private TupleSet computeLowerBound(List<Tuple> atoms, final PrimSig sig) throws Err {
   int n = sc.sig2scope(sig);
   TupleSet lower = factory.noneOf(1);
   for (PrimSig c : sig.children()) lower.addAll(computeLowerBound(atoms, c));
   TupleSet upper = lower.clone();
   boolean isExact = sc.isExact(sig);
   if (isExact || sig.isTopLevel())
     for (n = n - upper.size(); n > 0; n--) {
       Tuple atom = atoms.remove(atoms.size() - 1);
       // If MUST<SCOPE and s is exact, then add fresh atoms to both LOWERBOUND and UPPERBOUND.
       // If MUST<SCOPE and s is inexact but toplevel, then add fresh atoms to the UPPERBOUND.
       if (isExact) lower.add(atom);
       upper.add(atom);
     }
   lb.put(sig, lower);
   ub.put(sig, upper);
   return lower;
 }