Consider the following premises. There is at least one x_6 for which if x_6 were fast, then x_6 is a server. For all x_6, x_6 is fast if and only if x_6 is a server. Can we infer the following from them? For all x_6, the fact that x_6 were a server does not imply that x_6 is fast.
That contradicts the premises. Therefore the answer is no.