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 snowing and it is overcast. Thomas is making tea if and only if it is snowing.
It is snowing can be inferred via the simplification rule. It is overcast can be inferred via the simplification rule. If Thomas makes tea, then it is snowing can be inferred via the biconditional elimination rule. If it snows, then Thomas is making tea can be inferred via the biconditional elimination rule.