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: For all x_8, if x_8 were excited, then x_8 is climbing a mountain. For all x_8, if x_8 were an astronaut, then x_8 is not climbing a mountain. There is at least one x_8 for which if x_8 were a bartender, then x_8 is climbing a mountain. For all x_8, x_8 is excited or x_8 is a bartender.
There is at least one x_8 for which x_8 will climb a mountain can be inferred via the existential disjunction elimination rule.