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: There is at least one z for which z will climb a mountain if and only if z is bored.
There is at least one z for which if z climbs a mountain, then z is bored can be inferred via the existential biconditional elimination rule. There is at least one z for which if z were bored, then z is climbing a mountain can be inferred via the existential biconditional elimination rule.