(operator
 LOAD
 (params
  (<object> CARGO) (<rocket> ROCKET) (<place> PLACE))
 (preconds 
  (at <rocket> <place>)  (at <object> <place>))
 (effects 
  (in <object> <rocket>) (del at <object> <place>)))

(operator
 UNLOAD
 (params
  (<object> CARGO) (<rocket> ROCKET) (<place>  PLACE))
 (preconds 
  (at <rocket> <place>)  (in <object> <rocket>))
 (effects 
  (at <object> <place>) (del in <object> <rocket>)))

(operator
 MOVE
 (params
  (<rocket> ROCKET) (<from> PLACE) (<to> PLACE))
 (preconds 
  (has-fuel <rocket>) (at <rocket> <from>))
 (effects  
  (at <rocket> <to>) (del has-fuel <rocket>) (del at <rocket> <from>)))