[tlaplus] Removing "equivalents" from a set

Hello. I have a small problem that I haven't been able to solve:

What I'm trying to achieve is given a set of numbers, I want to partition it into smaller sets(in this case with size 2), and eliminate equivalent partitions to save resources.

6 hours later, I have arrived at this result, which is almost what I want:

s == { {{1}},
     {{2}},
     {{3}},
     {{4}},
     {{1, 2}},
     {{1, 3}},
     {{1, 4}},
     {{2, 3}},
     {{2, 4}},
     {{3, 4}},
     {{1}, {2, 3}},
     {{1}, {2, 4}},
     {{1}, {3, 4}},
     {{2}, {1, 3}},
     {{2}, {1, 4}},
     {{2}, {3, 4}},
     {{3}, {1, 2}},
     {{3}, {1, 4}},
     {{3}, {2, 4}},
     {{4}, {1, 2}},
     {{4}, {1, 3}},
     {{4}, {2, 3}},
     {{1, 2}, {3, 4}},
     {{1, 3}, {2, 4}},
     {{1, 4}, {2, 3}} }

What I am trying to do is to remove elements of this set, if the element's UNION is already contained in the set, giving me the following set:

{ {{1}},
     {{2}},
     {{3}},
     {{4}},
     {{1, 2}},
     {{1, 3}},
     {{1, 4}},
     {{2, 3}},
     {{2, 4}},
     {{3, 4}},
     {{1}, {2, 3}},
     {{1}, {2, 4}},
     {{1}, {3, 4}},
     {{2}, {3, 4}},
     {{1, 2}, {3, 4}} }

How could this be done? I have not found any way asserting that a predicate is true for every pair of elements in a set.