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_12, x_12 is a soldier and x_12 will go running. For all x_12, x_12 will climb a mountain or x_12 is a lawyer. There is at least one x_12 for which if x_12 climbs a mountain, then x_12 is a doctor. For all x_12, if x_12 were a lawyer, then x_12 is a doctor.
For all x_12, x_12 is a soldier can be inferred via the universal simplification rule. For all x_12, x_12 will go running can be inferred via the universal simplification rule. There is at least one x_12 for which x_12 is a doctor can be inferred via the existential disjunction elimination rule.