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_14, x_14 will not read a book. For all x_14, if x_14 were sad, then x_14 is reading a book. For all x_14, if x_14 were a mechanic, then x_14 is climbing a mountain. Charles is cooking if and only if Michael is a mechanic. For all x_14, if x_14 climbs a mountain, then x_14 is sad.
If Charles cooks, then Michael is a mechanic can be inferred via the biconditional elimination rule. If Michael were a mechanic, then Charles is cooking can be inferred via the biconditional elimination rule. For all x_14, x_14 is not sad can be inferred via the universal modus tollens rule. For all x_14, if x_14 were a mechanic, then x_14 is sad can be inferred via the universal transitivity rule. For all x_14, if x_14 climbs a mountain, then x_14 is reading a book can be inferred via the universal transitivity rule.