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_6 for which if x_6 were bored, then x_6 is climbing a mountain. For all x_6, x_6 will drink water. For all x_6, if x_6 climbs a mountain, then x_6 is a server. For all x_6, if x_6 were a server, then x_6 is not drinking water.
For all x_6, x_6 is not a server can be inferred via the universal modus tollens rule. There is at least one x_6 for which if x_6 were bored, then x_6 is a server can be inferred via the existential transitivity rule.