type Cell:
cell0
cell1
cell2
cell3
cell4
cell5
cell6
task Main(cell5 & cell6):
complete()
task Pickup(cell & !carry) on Cell as cell:
carry = pickup(cell)
effects:
cell = false
carry = true
task Dropoff(!cell & carry) on Cell as cell:
dropoff(cell, carry)
effects:
cell = true
carry = false