Consider the following premises. For all x_7, x_7 is sad or x_7 is not a server. For all x_7, x_7 is a server or x_7 is an electrician. There is at least one x_7 for which x_7 is sad if and only if x_7 is an electrician. Can we infer the following from them? If we can, name the inference rule being used: There is at least one x_7 for which x_7 is sad if and only if x_7 is an electrician.
That is one of the premises. Therefore, the answer is yes.