compare {1,2,..} vs {6,7,..}  # the return value here is my notion of "input"
if they are equal
    compare .. vs ..
    if left is heavier
        compare .. vs ..
        if they are equal, print ".. is heavier"  # this is my "output"
        if right is heavier, print ".. is lighter"
        ..
    ..
if right is heavier
    compare .. vs ..
    ..
..