Consider the following premises. Mary is playing squash if and only if Jennifer is drinking water. If Jessica were an astronaut, then Jennifer is drinking water. If Susan were a bartender, then Jessica is an astronaut. Can we infer the following from them? If we can, name the inference rule being used: If Susan were a bartender, then Mary is playing squash.
 From the fact that if Susan were a bartender, then Jessica is an astronaut, and that if Jessica were an astronaut, then Jennifer is drinking water we can infer that if Susan were a bartender, then Jennifer is drinking water via transitivity. From the fact that Mary is playing squash if and only if Jennifer is drinking water we can infer that if Jennifer drinks water, then Mary is playing squash via biconditional elimination. Finally, from the fact that if Susan were a bartender, then Jennifer is drinking water, and that if Jennifer drinks water, then Mary is playing squash we can infer that if Susan were a bartender, then Mary is playing squash via transitivity. Therefore, the answer is yes.