(fly plane1 city0 city2 fl2 fl1)
(refuel plane1 city2 fl1 fl2)
(board person1 plane1 city2)
(fly plane1 city2 city1 fl2 fl1)
(debark person1 plane1 city1)
(fly plane1 city1 city2 fl1 fl0)
; cost = 6 (unit cost)
