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: It is raining if and only if Joseph is making tea. If it rains, then Joseph is making tea. It is not raining.
If it rains, then Joseph is making tea can be inferred via the biconditional elimination rule. If Joseph makes tea, then it is raining can be inferred via the biconditional elimination rule. Joseph is not making tea can be inferred via the biconditional elimination rule.