Consider the following premises. For all x_12, x_12 will drink water if and only if x_12 is excited. For all x_12, x_12 is excited if and only if x_12 will play squash. There is at least one x_12 for which if x_12 plays squash, then x_12 is drinking water. Can we infer the following from them? If we can, name the inference rule being used: For all x_12, if is not true that x_12 is excited if and only if x_12 will drink water.
That contradicts the premises. Therefore the answer is no.