What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Mary is playing squash if and only if Susan is playing a game. James is listening to a song if and only if Mary is playing squash. It is overcast if and only if Susan is playing a game. James is not listening to a song.
If Mary plays squash, then Susan is playing a game. If James listens to a song, then Mary is playing squash. If it is overcast, then Susan is playing a game. If Susan plays a game, then Mary is playing squash. If Mary plays squash, then James is listening to a song. If Susan plays a game, then it is overcast. Mary is not playing squash.