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: For all x_9, x_9 will make tea if and only if x_9 is a lawyer. If Thomas makes tea, then it is windy. If it is windy, then Thomas is making tea. It is not windy.
Thomas is not making tea can be inferred via the modus tollens rule. For all x_9, if x_9 makes tea, then x_9 is a lawyer can be inferred via the universal biconditional elimination rule. For all x_9, if x_9 were a lawyer, then x_9 is making tea can be inferred via the universal biconditional elimination rule.