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_15, if x_15 were a bartender, then x_15 is a scientist. For all x_15, x_15 is a doctor if and only if x_15 is a janitor. For all x_15, if x_15 climbs a mountain, then x_15 is bored. For all x_15, x_15 will climb a mountain or x_15 is a bartender. For all x_15, if x_15 were bored, then x_15 is a scientist. For all x_15, if x_15 were a scientist, then x_15 is a doctor.
For all x_15, if x_15 were a bartender, then x_15 is a doctor can be inferred via the universal transitivity rule. For all x_15, if x_15 climbs a mountain, then x_15 is a scientist can be inferred via the universal transitivity rule. For all x_15, if x_15 were bored, then x_15 is a doctor can be inferred via the universal transitivity rule. For all x_15, if x_15 were a doctor, then x_15 is a janitor can be inferred via the universal biconditional elimination rule. For all x_15, if x_15 were a janitor, then x_15 is a doctor can be inferred via the universal biconditional elimination rule.