Consider the following premises. David is writing a letter or James is a carpenter. If David writes a letter, then James is a bartender. For all x_8, x_8 is a carpenter if and only if x_8 is a bartender. Can we infer the following from them? James is not a bartender.
 From the fact that for all x_8, x_8 is a carpenter if and only if x_8 is a bartender we can infer that for all x_8, if x_8 were a carpenter, then x_8 is a bartender. From the fact that for all x_8, if x_8 were a carpenter, then x_8 is a bartender we can infer that if James were a carpenter, then James is a bartender. Finally, from the fact that if David writes a letter, then James is a bartender, that if James were a carpenter, then James is a bartender, and that David is writing a letter or James is a carpenter we can infer that James is a bartender, which contradicts that James is not a bartender. Therefore, the answer is no.