Consider the following premises. For all x_12, if x_12 were an office clerk, then x_12 is a poet. There is at least one x_12 for which x_12 will not play a game or x_12 is an office clerk. For all x_12, x_12 will play a game or x_12 will write a letter. For all x_12, if x_12 were a poet, then x_12 is taking a plane. For all x_12, if x_12 writes a letter, then x_12 is a poet. Can we infer the following from them? If we can, name the inference rule being used: For all x_12, x_12 will not take a plane.
 From the fact that for all x_12, x_12 will play a game or x_12 will write a letter, and that there is at least one x_12 for which x_12 will not play a game or x_12 is an office clerk we can infer that there is at least one x_12 for which x_12 will write a letter or x_12 is an office clerk via existential resolution. From the fact that for all x_12, if x_12 writes a letter, then x_12 is a poet, that for all x_12, if x_12 were an office clerk, then x_12 is a poet, and that there is at least one x_12 for which x_12 will write a letter or x_12 is an office clerk we can infer that there is at least one x_12 for which x_12 is a poet via existential disjunction elimination. Finally, from the fact that for all x_12, if x_12 were a poet, then x_12 is taking a plane, and that there is at least one x_12 for which x_12 is a poet we can infer that there is at least one x_12 for which x_12 will take a plane via existential modus ponens, which contradicts that For all x_12, x_12 will not take a plane. Therefore, the answer is no.