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: It is late or Michael is a carpenter. If it is late, then Michael is playing tennis. For all x_8, x_8 is a carpenter if and only if x_8 will play tennis.
If Michael were sad, then it is late can be inferred via the rewriting rule. For all x_8, if x_8 were a carpenter, then x_8 is playing tennis can be inferred via the universal biconditional elimination rule. For all x_8, if x_8 plays tennis, then x_8 is a carpenter can be inferred via the universal biconditional elimination rule.