# the sort does this:
(
  [ 8, "viii"],
  [11, "xi"],
  [ 9, "ix"],
  [ 4, "vi"],
  [ 3, "iii"],
) --> (
  [ 3, "iii"],
  [ 9, "ix"],
  [ 4, "vi"],
  [ 8, "viii"],
  [11, "xi"],
)