What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Mary is drinking water if and only if Jessica is a mechanic. Jessica is a mechanic or Linda is listening to a song. Mary is drinking water or Linda is not listening to a song.
If Linda listens to a song, then Mary is drinking water. If Mary drinks water, then Jessica is a mechanic. If Jessica were a mechanic, then Mary is drinking water.