How to Exclude Two Ilist

Question

I have a program where I first get the List of Integer array by calling a method whose return type is IEnumerable<int[]>
var result = Myclass.GetNumbers(someInputVal);

say - result contains [0] - {1,2,3}
                             [1]- {4,5,6}

public static IEnumerable<int[]> GetNumbers (int someInputval)
{
List<int[]> result = new List<int[]>();

// Number processing done here
return result;
}
And I have another List of int[], say result1

List<int[]> result1 = new List<int[]> {
                new int[]{1,2,3}
                ,new int[]{7,8,9}
            };

Now, How do I compare result with result1 and exclude the value which are common between result and result1 from result

So, the result list should have only {{4,5,6} .

I am not sure how will I be able to achieve this efficiently. I will have many InputSet's that I will need to check in the "result".
Appreciate your help.