What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Thomas is a nurse if and only if Mary is running. If Susan plays squash, then Mary is running. Susan is playing squash if and only if it is raining. Thomas is not a nurse.
If Thomas were a nurse, then Mary is running. If Susan plays squash, then it is raining. If Mary goes running, then Thomas is a nurse. If it rains, then Susan is playing squash. Mary is not running.