Consider the following premises. Barbara is reading a book and it is sunny. Patricia is a carpenter if and only if Jessica is playing a game. For all x_23, x_23 will not play a game. Can we infer the following from them? If we can, name the inference rule being used: Patricia is a carpenter.
 From the fact that for all x_23, x_23 will not play a game we can infer that Jessica is not playing a game via universal instantiation. Finally, from the fact that Patricia is a carpenter if and only if Jessica is playing a game, and that Jessica is not playing a game we can infer that Patricia is not a carpenter via biconditional elimination, which contradicts that Patricia is a carpenter. Therefore, the answer is no.