public static IExpression GetMarriedExpression()
        {
            IExpression julie   = new TerminalExpression("julie");
            IExpression married = new TerminalExpression("married");

            return(new AndExpression(julie, married));
        }
        public static IExpression GetMaleExpression()
        {
            IExpression robert = new TerminalExpression("rober");
            IExpression luc    = new TerminalExpression("luc");

            return(new OrExpression(robert, luc));
        }