Consider the following premises. Karen is making tea if and only if Patricia is a cashier. For all x_11, x_11 is a sailor. Karen is making tea if and only if Jennifer is a bartender. Jennifer is not a bartender. Can we infer the following from them? If we can, name the inference rule being used: Patricia is a cashier.
 From the fact that Karen is making tea if and only if Jennifer is a bartender, and that Jennifer is not a bartender we can infer that Karen is not making tea via biconditional elimination. Finally, from the fact that Karen is making tea if and only if Patricia is a cashier, and that Karen is not making tea we can infer that Patricia is not a cashier via biconditional elimination, which contradicts that Patricia is a cashier. Therefore, the answer is no.