as the near between towns increase , the sail of the vision will decrease
if bear_down_on occurs then sail occurs. mizzen is fore_and_aft_sail. decrease_in_flammability is decrease. if scale_down occurs then decrease occurs. sailboats_only_move_if_wind is blowing. mv_arctic_sunrise is ship. square_sail is sail. near_vision is sight. if sailplane occurs then fly occurs.