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;

}