array-intersect
Opposite of array_intersect?
That sounds like a job for array_diff. Returns an array containing all the entries from array1 that are not present in any of the other arrays.
rails – Finding intersections between multiple arrays
Use the & method of Array which is for set intersection. For example: > [1,2,3] & [2,3,4] & [0,2,6] => [2]