
[;1m  intersection_of_family(Family)[0m

  Returns the intersection of family [;;4mFamily[0m.

  Intersecting an empty family exits the process with a [;;4mbadarg[0m
  message.

    1> F = sofs:family([{a,[0,2,4]},{b,[0,1,2]},{c,[2,3]}]),
    S = sofs:intersection_of_family(F),
    sofs:to_external(S).
    [2]
