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: If Robert were a poet, then it is not overcast. It is overcast. If it is late, then it is not raining. It is raining.
Robert is not a poet can be inferred via the modus tollens rule. It is not late can be inferred via the modus tollens rule. It is overcast and it is raining can be inferred via the conjunction rule. It is raining and it is overcast can be inferred via the conjunction rule.