What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: It is late or William is playing squash. Elisabeth is a doctor or Michael is a nurse. If it is late, then John is running. Elisabeth is not a doctor. If William plays squash, then John is running.
Michael is a nurse can be inferred via the disjunctive syllogism rule. John is running can be inferred via the disjunction elimination rule.