Consider the following premises. If it snows, then Robert is taking a plane. For all x_10, x_10 will not take a plane. Barbara is a bartender if and only if it is snowing. Can we infer the following from them? Barbara is a bartender.
 From the fact that for all x_10, x_10 will not take a plane we can infer that Robert is not taking a plane. From the fact that if it snows, then Robert is taking a plane, and that Robert is not taking a plane we can infer that it is not snowing. Finally, from the fact that Barbara is a bartender if and only if it is snowing, and that it is not snowing we can infer that Barbara is not a bartender, which contradicts that Barbara is a bartender. Therefore, the answer is no.