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: forall x_14: P_14(x_14) <-> R(x_14). t <-> R(f).
t -> R(f) can be inferred via the biconditional elimination rule. R(f) -> t can be inferred via the biconditional elimination rule. forall x_14: P_14(x_14) -> R(x_14) can be inferred via the universal biconditional elimination rule. forall x_14: R(x_14) -> P_14(x_14) can be inferred via the universal biconditional elimination rule.