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_10, x_10 is a taxi driver. For all x_10, if x_10 were a taxi driver, then x_10 is an office clerk. For all x_10, if x_10 were a carpenter, then x_10 is an astronaut. For all x_10, if x_10 were an office clerk, then x_10 is a soldier. For all x_10, x_10 is a carpenter.
For all x_10, x_10 is an office clerk can be inferred via the universal modus ponens rule. For all x_10, x_10 is an astronaut can be inferred via the universal modus ponens rule. For all x_10, if x_10 were a taxi driver, then x_10 is a soldier can be inferred via the universal transitivity rule. For all x_10, x_10 is a taxi driver and x_10 is a carpenter can be inferred via the universal conjunction rule. For all x_10, x_10 is a carpenter and x_10 is a taxi driver can be inferred via the universal conjunction rule.