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_8, x_8 will take a plane if and only if x_8 will go running. For all x_8, x_8 will take a plane if and only if x_8 will go running.
For all x_8, if x_8 takes a plane, then x_8 is running can be inferred via the universal biconditional elimination rule. For all x_8, if x_8 takes a plane, then x_8 is running can be inferred via the universal biconditional elimination rule. For all x_8, if x_8 goes running, then x_8 is taking a plane can be inferred via the universal biconditional elimination rule. For all x_8, if x_8 goes running, then x_8 is taking a plane can be inferred via the universal biconditional elimination rule.