Consider the following premises. If Thomas were an office clerk, then Linda is an artist. Linda is not an artist. For all x_16, x_16 is an office clerk if and only if x_16 will write a letter. Can we infer the following from them? If we can, name the inference rule being used: Thomas is not writing a letter or it is cloudy.
 From the fact that for all x_16, x_16 is an office clerk if and only if x_16 will write a letter we can infer that Thomas is an office clerk if and only if Thomas is writing a letter via universal instantiation. From the fact that if Thomas were an office clerk, then Linda is an artist, and that Linda is not an artist we can infer that Thomas is not an office clerk via modus tollens. From the fact that Thomas is an office clerk if and only if Thomas is writing a letter, and that Thomas is not an office clerk we can infer that Thomas is not writing a letter via biconditional elimination. Finally, from the fact that Thomas is not writing a letter we can infer that Thomas is not writing a letter or it is cloudy via addition. Therefore, the answer is yes.