Consider the following premises. Richard is drinking water. For all x_17, x_17 will not drink water. Can we infer the following from them? If we can, name the inference rule being used: It is late or Charles is sad.
 From the fact that for all x_17, x_17 will not drink water we can infer that Richard is not drinking water via universal instantiation. From the fact that Richard is drinking water we can infer that Richard is drinking water or it is late via addition. From the fact that Richard is drinking water or it is late, and that Richard is not drinking water we can infer that it is late via disjunctive syllogism. Finally, from the fact that it is late we can infer that it is late or Charles is sad via addition. Therefore, the answer is yes. Notice, however, that the premises were contradictory, so we can infer anything from them.