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_14, if x_14 climbs a mountain, then x_14 is a lawyer. For all x_14, if x_14 were a lawyer, then x_14 is climbing a mountain. There is at least one x_14 for which if x_14 were a lawyer, then x_14 is an artist. For all x_14, x_14 will climb a mountain if and only if x_14 is a bartender.
There is at least one x_14 for which if x_14 climbs a mountain, then x_14 is an artist can be inferred via the existential transitivity rule. For all x_14, x_14 will climb a mountain if and only if x_14 is a lawyer can be inferred via the universal biconditional introduction rule. For all x_14, x_14 is a lawyer if and only if x_14 will climb a mountain can be inferred via the universal biconditional introduction rule. For all x_14, if x_14 climbs a mountain, then x_14 is a bartender can be inferred via the universal biconditional elimination rule. For all x_14, if x_14 were a bartender, then x_14 is climbing a mountain can be inferred via the universal biconditional elimination rule.