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_6, if x_6 were a carpenter, then x_6 is a bartender. For all x_6, x_6 is not a sailor or x_6 is a mechanic. For all x_6, if x_6 were a bartender, then x_6 is taking a plane. For all x_6, x_6 is a sailor or x_6 is a carpenter. For all x_6, if x_6 were a mechanic, then x_6 is a bartender.
For all x_6, if x_6 were a carpenter, then x_6 is taking a plane can be inferred via the universal transitivity rule. For all x_6, if x_6 were a mechanic, then x_6 is taking a plane can be inferred via the universal transitivity rule. For all x_6, x_6 is a carpenter or x_6 is a mechanic can be inferred via the universal resolution rule.