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 not an electrician. For all x_10, x_10 is a mechanic if and only if x_10 is an electrician. There is at least one x_10 for which x_10 will read a book. For all x_10, x_10 is not a cashier or x_10 is a lawyer. For all x_10, x_10 is a cashier or x_10 is a mechanic.
For all x_10, x_10 is a mechanic or x_10 is a lawyer can be inferred via the universal resolution rule. For all x_10, if x_10 were a mechanic, then x_10 is an electrician can be inferred via the universal biconditional elimination rule. For all x_10, if x_10 were an electrician, then x_10 is a mechanic can be inferred via the universal biconditional elimination rule. For all x_10, x_10 is not a mechanic can be inferred via the universal biconditional elimination rule.