Consider the following premises. Mary is a lawyer if and only if it is late. For all x_6, if x_6 were a lawyer, then x_6 is taking a plane. For all x_6, x_6 will not take a plane. Can we infer the following from them? It is late.
 From the fact that for all x_6, if x_6 were a lawyer, then x_6 is taking a plane, and that for all x_6, x_6 will not take a plane we can infer that for all x_6, x_6 is not a lawyer. From the fact that for all x_6, x_6 is not a lawyer we can infer that Mary is not a lawyer. Finally, from the fact that Mary is a lawyer if and only if it is late, and that Mary is not a lawyer we can infer that it is not late, which contradicts that It is late. Therefore, the answer is no.