Consider the following premises. Robert is a scientist if and only if it is snowing. Linda is not drinking water. Linda is drinking water or it is snowing. Can we infer the following from them? If we can, name the inference rule being used: Robert is a scientist.
 From the fact that Linda is drinking water or it is snowing, and that Linda is not drinking water we can infer that it is snowing via disjunctive syllogism. From the fact that Robert is a scientist if and only if it is snowing we can infer that if it snows, then Robert is a scientist via biconditional elimination. Finally, from the fact that if it snows, then Robert is a scientist, and that it is snowing we can infer that Robert is a scientist via modus ponens. Therefore, the answer is yes.