Consider the following premises. David is not a carpenter. For all x_8, if x_8 makes tea, then x_8 is a carpenter. If it snows, then David is making tea. For all x_8, if x_8 were a carpenter, then x_8 is making tea. Can we infer the following from them? If we can, name the inference rule being used: It is not snowing.
 From the fact that for all x_8, if x_8 makes tea, then x_8 is a carpenter, and that for all x_8, if x_8 were a carpenter, then x_8 is making tea we can infer that for all x_8, x_8 will make tea if and only if x_8 is a carpenter via universal biconditional introduction. From the fact that for all x_8, x_8 will make tea if and only if x_8 is a carpenter we can infer that David is making tea if and only if David is a carpenter via universal instantiation. From the fact that David is making tea if and only if David is a carpenter, and that David is not a carpenter we can infer that David is not making tea via biconditional elimination. Finally, from the fact that if it snows, then David is making tea, and that David is not making tea we can infer that it is not snowing via modus tollens. Therefore, the answer is yes.