public PathFormula getSelectedFormula() {
		if (selectedFormula == null) {
			if (first.isSelected()) {
				if (combo1.getSelectedItem().equals(IT_IS_POSSIBLE)) {
					selectedFormula = new EventuallyExistsPath(state1.getSelectedFormula());
				} else if (combo1.getSelectedItem().equals(IT_IS_NOT_POSSIBLE)) {
					selectedFormula = new AlwaysAllPaths(new NotStateFormula(state1.getSelectedFormula()));
				}
			} else if (second.isSelected()) {
				selectedFormula = new Implies(state2.getSelectedFormula(), state3.getSelectedFormula());
			} else if (third.isSelected()) {
				if (combo2.getSelectedItem().equals(CAN)) {
					selectedFormula = new EventuallyAllPaths(state4.getSelectedFormula());
				} else if (combo2.getSelectedItem().equals(MUST)) {
					selectedFormula = new AlwaysAllPaths(state4.getSelectedFormula());
				}
			}
		}
		return selectedFormula;
	}