private void proveQuery(String content) {
        try {
            Evaluator evaluator = new Evaluator(new RobinsonUnificationStrategy(), knowledgeBase);
            boolean result = evaluator.prove(
                    new ConsoleEvaluationHandler(System.out, console), parser.parsePredicates(content));
            if (!result) {
                System.out.println("false");
            }
        } catch (InfiniteRecursionException ex) {
            System.out.println("ERROR: Infinite recursion.");
        } catch (EvaluationException ex) {
            System.out.println("ERROR: General evaluation error. ['" + ex.getMessage() + "'].");
        } catch (ParseException ex) {
            System.out.println("ERROR: The given query is invalid ['" + ex.getMessage() + "'].");
        }
    }