//Rule: Julie is a married women
        public static IExpression getMarriedWomanExpression()
        {
            IExpression julie   = new TerminalExpression("Julie");
            IExpression married = new TerminalExpression("Married");

            return(new AndExpression(julie, married));
        }
        //Rule: Robert and John are male
        public static IExpression getMaleExpression()
        {
            IExpression robert = new TerminalExpression("Robert");
            IExpression john   = new TerminalExpression("John");

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