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_7, x_7 will cook or x_7 is rich. For all x_7, x_7 will cook if and only if x_7 will work. For all x_7, if x_7 works, then x_7 is climbing a mountain. For all x_7, if x_7 were rich, then x_7 is working.
For all x_7, if x_7 were rich, then x_7 is climbing a mountain can be inferred via the universal transitivity rule. For all x_7, if x_7 cooks, then x_7 is working can be inferred via the universal biconditional elimination rule. For all x_7, if x_7 works, then x_7 is cooking can be inferred via the universal biconditional elimination rule.