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 overcast, then it is cloudy. It is not cloudy. If James makes tea, then it is cold. If it is cold, then James is making tea. If it is cold, then it is overcast.
It is not overcast can be inferred via the modus tollens rule. If James makes tea, then it is overcast can be inferred via the transitivity rule. If it is cold, then it is cloudy can be inferred via the transitivity rule. James is making tea if and only if it is cold can be inferred via the biconditional introduction rule. It is cold if and only if James is making tea can be inferred via the biconditional introduction rule.