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 William makes tea, then Linda is climbing a mountain. Linda is not climbing a mountain. It is snowing if and only if William is making tea.
William is not making tea can be inferred via the modus tollens rule. If it snows, then William is making tea can be inferred via the biconditional elimination rule. If William makes tea, then it is snowing can be inferred via the biconditional elimination rule.