Enumerable.except Method
        
 Produces the set difference of two sequences, optionally using the specified equality comparer
 to compare values.
 
         
         
        
            
 This method is static. 
        Parameters
        
            - first
            
 
            - 
                
Type: IEnumerable
An enumerable whose elements
 that are not also in the second will be returned. 
            - second
            
 
            - 
                
Type: IEnumerable
An enumerable whose elements that also
 occur in the first sequence will cause those elements to be removed from the returned sequence. 
            - equalityComparer
            
 
            - 
                
Type: IEqualityComparer
An equality comparer to compare values.
Optional: True 
        
        Return Value
        
Type: IEnumerable
        
A sequence that contains the set difference of the elements of two sequences.