What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: There is at least one x_5 for which if x_5 were a nurse, then x_5 is a lawyer. For all x_5, if x_5 were excited, then x_5 is a lawyer. For all x_5, if x_5 were a lawyer, then x_5 is excited.
There is at least one x_5 for which if x_5 were a nurse, then x_5 is excited can be inferred via the existential transitivity rule. For all x_5, x_5 is excited if and only if x_5 is a lawyer can be inferred via the universal biconditional introduction rule. For all x_5, x_5 is a lawyer if and only if x_5 is excited can be inferred via the universal biconditional introduction rule.