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, x is an office clerk if and only if x will read a book. For all x, x will not read a book.
For all x, if x were an office clerk, then x is reading a book can be inferred via the universal biconditional elimination rule. For all x, if x reads a book, then x is an office clerk can be inferred via the universal biconditional elimination rule. For all x, x is not an office clerk can be inferred via the universal biconditional elimination rule.