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 it is sunny, then James is a bartender. It is sunny or it is cloudy. James is not a bartender. It is overcast if and only if it is cloudy.
It is not sunny can be inferred via the modus tollens rule. If it is overcast, then it is cloudy can be inferred via the biconditional elimination rule. If it is cloudy, then it is overcast can be inferred via the biconditional elimination rule.