 
            
            
            
            
                23 Jan
                
                    2009
                
            
            
                23 Jan
                
                '09
                
            
            
            
        
    
                9:05 a.m.
            
        I noticed that in problem 4, the use of Either is needed, which hasn't been introduced yet. I've gotten stuck on 8/9, and am wondering if there is something needed that hasn't been introduced yet as well? Put another way, can problem 8/9 be done given the parts of the language introduced thus far? Regards, Michael Litchard