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 not cook. Susan is a nurse if and only if Elisabeth is taking a plane. For all x_8, x_8 will cook if and only if x_8 will take a plane.
If Susan were a nurse, then Elisabeth is taking a plane can be inferred via the biconditional elimination rule. If Elisabeth takes a plane, then Susan is a nurse can be inferred via the biconditional elimination rule. For all x_8, if x_8 cooks, then x_8 is taking a plane can be inferred via the universal biconditional elimination rule. For all x_8, if x_8 takes a plane, then x_8 is cooking can be inferred via the universal biconditional elimination rule. For all x_8, x_8 will not take a plane can be inferred via the universal biconditional elimination rule.