func ordered(a, b) {
    (a <=> b) < 0
}

for p in [
    Pair([1,2,4], [1,2,4]),
    Pair([1,2,4], [1,2]  ),
    Pair([1,2],   [1,2,4]),
] {
    var a = p.first
    var b = p.second
    var before = ordered(a, b)
    say "#{a} comes before #{b} : #{before}"
}