What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If Michael takes a plane, then William is playing a game. If William plays a game, then Michael is taking a plane. If Michael takes a plane, then William is playing a game.
Michael is taking a plane if and only if William is playing a game. William is playing a game if and only if Michael is taking a plane. William is playing a game if and only if Michael is taking a plane. Michael is taking a plane if and only if William is playing a game.