(operator
 move
 (params
  (<b> Object) (<x> Object) (<y> Object))
 (preconds
  (on <b> <x>) (clear <b>) (clear <y>))
 (effects
  (on <b> <y>) (clear <x>) (del on <b> <x>) (del clear <y>)))

(operator
 movetotable
 (params
  (<b> Object) (<x> Object))
 (preconds
  (on <b> <x>) (clear <b>))
 (effects
  (on <b> Table) (clear <x>) (del on <b> <x>)))

(operator
 movefromtable
 (params
  (<b> Object) (<x> Object))
 (preconds
  (on <b> Table) (clear <b>) (clear <x>))
 (effects
  (on <b> <x>) (del clear <x>) (del on <b> Table)))