What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is late or William is taking a plane. Jessica is not working. Mary is playing squash if and only if it is late. If it snows, then Jessica is working. Mary is not playing squash.
It is not snowing. Jessica is not working and Mary is not playing squash. Mary is not playing squash and Jessica is not working. If Mary plays squash, then it is late. If it is late, then Mary is playing squash. It is not late.