[[(0, 1), (2, 3), (4, 5)], [(0, 1), (2, 4), (3, 5)], [(0, 1), (2, 5), (3, 4
    )], [(0, 2), (1, 3), (4, 5)], [(0, 2), (1, 4), (3, 5)], [(0, 2), (1, 5),
    (3, 4)], [(0, 3), (1, 2), (4, 5)], [(0, 3), (1, 4), (2, 5)], [(0, 3), (
    1, 5), (2, 4)], [(0, 4), (1, 2), (3, 5)], [(0, 4), (1, 3), (2, 5)], [(0,
    4), (1, 5), (2, 3)], [(0, 5), (1, 2), (3, 4)], [(0, 5), (1, 3), (2, 4)],
    [(0, 5), (1, 4), (2, 3)]]
How to split a list into pairs in all possible ways