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: exists x: U_1(x) <-> Q(x).
exists x: U_1(x) -> Q(x) can be inferred via the existential biconditional elimination rule. exists x: Q(x) -> U_1(x) can be inferred via the existential biconditional elimination rule.