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, if x_10 reads a book, then x_10 is an electrician. For all x_10, if x_10 were an electrician, then x_10 is an astronaut. For all x_10, x_10 is an astronaut or x_10 will read a book. For all x_10, if x_10 were an astronaut, then x_10 is an electrician.
For all x_10, if x_10 reads a book, then x_10 is an astronaut can be inferred via the universal transitivity rule. For all x_10, x_10 is an electrician can be inferred via the universal disjunction elimination rule. For all x_10, x_10 is an electrician if and only if x_10 is an astronaut can be inferred via the universal biconditional introduction rule. For all x_10, x_10 is an astronaut if and only if x_10 is an electrician can be inferred via the universal biconditional introduction rule.