static L<TripleWeb> ai_thoughtSpace_queryTriples(Symbol a, Symbol b, Symbol c, AbstractThoughtSpace ts) {
  L<TripleWeb> l = null;
  if (!isDollarVar(a)) l = shortestListUnlessNull2(l, ts.getTriples(a, 0));
  if (!isDollarVar(b)) l = shortestListUnlessNull2(l, ts.getTriples(b, 1));
  if (!isDollarVar(c)) l = shortestListUnlessNull2(l, ts.getTriples(c, 2));
  ret l;
}