What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? William is playing a game. Barbara is bored. If Charles were a carpenter, then James is playing squash. If James plays squash, then Charles is a carpenter. If Charles were a carpenter, then William is not playing a game.
Charles is not a carpenter. If James plays squash, then William is not playing a game. William is playing a game and Barbara is bored. Barbara is bored and William is playing a game. Charles is a carpenter if and only if James is playing squash. James is playing squash if and only if Charles is a carpenter.