Consider the following premises. William is not writing a letter or Richard is climbing a mountain. For all x_12, x_12 will write a letter. Can we infer the following from them? Jessica is running or Richard is climbing a mountain.
 From the fact that for all x_12, x_12 will write a letter we can infer that William is writing a letter. From the fact that William is writing a letter we can infer that William is writing a letter or Jessica is running. Finally, from the fact that William is writing a letter or Jessica is running, and that William is not writing a letter or Richard is climbing a mountain we can infer that Jessica is running or Richard is climbing a mountain. Therefore, the answer is yes.