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_11, if x_11 were a taxi driver, then x_11 is reading a book. For all x_11, x_11 is a police officer or x_11 is a doctor. There is at least one x_11 for which if x_11 climbs a mountain, then x_11 is reading a book. For all x_11, x_11 is not a police officer. For all x_11, x_11 will climb a mountain or x_11 is a taxi driver.
For all x_11, x_11 is a doctor can be inferred via the universal disjunctive syllogism rule. There is at least one x_11 for which x_11 will read a book can be inferred via the existential disjunction elimination rule.