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 an astronaut, then x_6 is a mechanic. For all x_6, if x_6 climbs a mountain, then x_6 is an astronaut. For all x_6, x_6 is an astronaut or x_6 will not play squash. For all x_6, x_6 will climb a mountain or x_6 will play squash.
For all x_6, if x_6 climbs a mountain, then x_6 is a mechanic can be inferred via the universal transitivity rule. For all x_6, if x_6 plays squash, then x_6 is an astronaut can be inferred via the universal rewriting rule.