What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If Joseph were a scientist, then it is snowing. It is not overcast. If it snows, then Joseph is a scientist. Joseph is a scientist if and only if it is overcast.
Joseph is a scientist if and only if it is snowing. It is snowing if and only if Joseph is a scientist. If Joseph were a scientist, then it is overcast. If it is overcast, then Joseph is a scientist. Joseph is not a scientist.