Consider the following premises. For all x_12, if x_12 were a writer, then x_12 is playing squash. For all x_12, if x_12 were a poet, then x_12 is not running. There is at least one x_12 for which x_12 will go running. For all x_12, x_12 is a poet if and only if x_12 will play squash. Can we infer the following from them? There is at least one x_12 for which x_12 is not a writer.
 From the fact that for all x_12, if x_12 were a poet, then x_12 is not running, and that there is at least one x_12 for which x_12 will go running we can infer that there is at least one x_12 for which x_12 is not a poet. From the fact that for all x_12, x_12 is a poet if and only if x_12 will play squash, and that there is at least one x_12 for which x_12 is not a poet we can infer that there is at least one x_12 for which x_12 will not play squash. Finally, from the fact that for all x_12, if x_12 were a writer, then x_12 is playing squash, and that there is at least one x_12 for which x_12 will not play squash we can infer that there is at least one x_12 for which x_12 is not a writer. Therefore, the answer is yes.