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 z_1, if z_1 climbs a mountain, then z_1 is running. There is at least one z_1 for which z_1 is an artist or z_1 will not go running. For all z_1, if z_1 goes running, then z_1 is climbing a mountain.
There is at least one z_1 for which if z_1 goes running, then z_1 is an artist can be inferred via the existential rewriting rule. For all z_1, z_1 will climb a mountain if and only if z_1 will go running can be inferred via the universal biconditional introduction rule. For all z_1, z_1 will go running if and only if z_1 will climb a mountain can be inferred via the universal biconditional introduction rule.