What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If David makes tea, then it is snowing. If Barbara plays a game, then Michael is listening to a song. If it snows, then Barbara is playing a game. David is making tea if and only if Michael is listening to a song.
If David makes tea, then Barbara is playing a game. If it snows, then Michael is listening to a song. If David makes tea, then Michael is listening to a song. If Michael listens to a song, then David is making tea.