static int prolog_tryToDeriveLastLine_maxSteps = 1000;

static bool prolog_tryToDeriveLastLine(S data) {
  // make Prolog interpreter
  new Prolog p;
  p.upperCaseVariables = true;
  //p.showStuff = true;
  p.addTheory(dropLastLine(rtrim(data)), programID());
  Lisp pivot = nlParse(lastLine(rtrim(data)));
  // try to derive last statement from the rest
  new LinkedHashSet<Lisp> set;
  Collector<Lisp> c = limitedSearchCollector(set, prolog_tryToDeriveLastLine_maxSteps, pivot);
  p.rewriteInto(c);
  print("Found " + nl(set, "statement") + ":");
  //printIndent(snlAllToText(l));
  printIndent(nlUnparseLines(asList(set)));
  print();
  print("Pivot statement: " + nlUnparse(pivot));
  bool found = set.contains(pivot);
  print("Pivot statement found? " + yn(found));
  ret found;
}