public void run() {
		Map<String, Term> solution;
		// Variable X = new Variable("X");
		//
		Query q2 = new Query("child_of(joe,ralf)");
		System.err.println("child_of(joe,ralf) is " + (q2.hasSolution() ? "provable" : "not provable"));
		new Query("sleep(?)", new Term[] { new org.jpl7.Integer(delay) }).hasSolution();
		//
		Query q3 = new Query("descendent_of(steve,ralf)");
		System.err.println("descendent_of(steve,ralf) is " + (q3.hasSolution() ? "provable" : "not provable"));
		delay();
		//
		Query q4 = new Query("descendent_of(X, ralf)");
		solution = q4.oneSolution();
		System.err.println("first solution of descendent_of(X, ralf)");
		System.err.println("X = " + solution.get("X"));
		delay();
		//
		Map<String, Term>[] solutions = q4.allSolutions();
		System.err.println("all solutions of descendent_of(X, ralf)");
		for (int i = 0; i < solutions.length; i++) {
			System.err.println("X = " + solutions[i].get("X"));
		}
		delay();
		//
		System.err.println("each solution of descendent_of(X, ralf)");
		while (q4.hasMoreSolutions()) {
			solution = q4.nextSolution();
			System.err.println("X = " + solution.get("X"));
		}
		delay();
		//
		Query q5 = new Query("descendent_of(X, Y)");
		System.err.println(id + ": each solution of descendent_of(X, Y)");
		while (q5.hasMoreSolutions()) {
			solution = q5.nextSolution();
			System.err.println(id + ": X = " + solution.get("X") + ", Y = " + solution.get("Y"));
			delay();
		}
	}