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: There is at least one x_13 for which x_13 will play squash. For all x_13, if x_13 were fast, then x_13 is cooking. For all x_13, x_13 is fast or x_13 is a carpenter. For all x_13, x_13 will cook if and only if x_13 is a carpenter. For all x_13, if x_13 cooks, then x_13 is a carpenter.
For all x_13, if x_13 were fast, then x_13 is a carpenter can be inferred via the universal transitivity rule. For all x_13, if x_13 cooks, then x_13 is a carpenter can be inferred via the universal biconditional elimination rule. For all x_13, if x_13 were a carpenter, then x_13 is cooking can be inferred via the universal biconditional elimination rule.