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, if x sleeps, then x is climbing a mountain. There is at least one x for which x will sleep if and only if x will climb a mountain.
There is at least one x for which if x sleeps, then x is climbing a mountain can be inferred via the existential biconditional elimination rule. There is at least one x for which if x climbs a mountain, then x is sleeping can be inferred via the existential biconditional elimination rule.