What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is windy if and only if Linda is listening to a song. Linda is listening to a song if and only if Joseph is writing a letter.
If it is windy, then Linda is listening to a song. If Linda listens to a song, then Joseph is writing a letter. If Linda listens to a song, then it is windy. If Joseph writes a letter, then Linda is listening to a song.