Consider the following premises. For all x_6, if x_6 goes running, then x_6 is a lawyer. For all x_6, x_6 is not a sailor or x_6 will go running. For all x_6, x_6 is a sailor or x_6 is a musician. For all x_6, x_6 is a lawyer if and only if x_6 is a musician. Can we infer the following from them? If we can, name the inference rule being used: For all x_6, x_6 is a lawyer.
 From the fact that for all x_6, x_6 is a sailor or x_6 is a musician, and that for all x_6, x_6 is not a sailor or x_6 will go running we can infer that for all x_6, x_6 is a musician or x_6 will go running via universal resolution. From the fact that for all x_6, x_6 is a lawyer if and only if x_6 is a musician we can infer that for all x_6, if x_6 were a musician, then x_6 is a lawyer via universal biconditional elimination. Finally, from the fact that for all x_6, if x_6 were a musician, then x_6 is a lawyer, that for all x_6, if x_6 goes running, then x_6 is a lawyer, and that for all x_6, x_6 is a musician or x_6 will go running we can infer that for all x_6, x_6 is a lawyer via universal disjunction elimination. Therefore, the answer is yes.