Investigating why NUnit Assert.AreEqual doesn't work for identitical tuples with arrays

gistfile1.txt

> z;;

val it : int [] * int = ([|1|], 1)

> p;;

val it : int [] * int = ([|1|], 1)

> z.Equals(p);;

val it : bool = false

> z = p;;

val it : bool = true

> 

// working tuples

let t = (1,2);;

val t : int * int = (1, 2)

let t2 = (1, 2);;

val t2 : int * int = (1, 2)

t.GetHashCode();;

val it : int = 33

t2.GetHashCode();;

val it : int = 33

Special stuff for arrays in NUnit:

 /// <summary>
        /// Helper method to compare two arrays
        /// </summary>
        private bool ArraysEqual(Array x, Array y, ref Tolerance tolerance)
        {
            int rank = x.Rank;

            if (rank != y.Rank)
                return false;

            for (int r = 1; r < rank; r++)
                if (x.GetLength(r) != y.GetLength(r))
                    return false;

            return EnumerablesEqual((IEnumerable)x, (IEnumerable)y, ref tolerance);
        }

private bool EnumerablesEqual(IEnumerable x, IEnumerable y, ref Tolerance tolerance)
        {
            IEnumerator expectedEnum = x.GetEnumerator();
            IEnumerator actualEnum = y.GetEnumerator();

            int count;
            for (count = 0; ; count++)
            {
                bool expectedHasData = expectedEnum.MoveNext();
                bool actualHasData = actualEnum.MoveNext();

                if (!expectedHasData && !actualHasData)
                    return true;

                if (expectedHasData != actualHasData ||
                    !AreEqual(expectedEnum.Current, actualEnum.Current, ref tolerance))
                {
                    FailurePoint fp = new FailurePoint();
                    fp.Position = count;
                    fp.ExpectedHasData = expectedHasData;
                    if (expectedHasData)
                        fp.ExpectedValue = expectedEnum.Current;
                    fp.ActualHasData = actualHasData;
                    if (actualHasData)
                        fp.ActualValue = actualEnum.Current;
                    failurePoints.Insert(0, fp);
                    return false;
                }
            }
        }