public class PrologPlusCG {
// Construct the application
public PrologPlusCG() {
PPCGEnv env = new PPCGEnv();
PrologPlusCGFrame frame = new PrologPlusCGFrame(env, false);
PPCGIO_GUI io = new PPCGIO_GUI(env, frame);
env.io = io;
frame.validate();
//Center the window
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();