Returns

{Object|Boolean}:

A prop function should either return a Boolean which indicates if aValue and bValue are equal or an AlgebraResult object that details information about the union, intersection, and difference of aValue and bValue.

An AlgebraResult object has the following values:

• union - A value the represents the union of A and B.
• intersection - A value that represents the intersection of A and B.
• difference - A value that represents all items in A that are not in B.
• count - The count of the items in A.

For example, if you had a colors property and A is ["Red","Blue"] and B is ["Green","Yellow","Blue"], the AlgebraResult object might look like:

{
    union: [ "Red", "Blue", "Green", "Yellow" ],
    intersection: [ "Blue" ],
    difference: [ "Red" ],
    count: 2000
}

The count is 2000 because there might be 2000 items represented by colors "Red" and "Blue". Often the real number can not be known.