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_8, x_8 is a carpenter if and only if x_8 will read a book. If Elisabeth works, then Richard is a carpenter.
For all x_8, if x_8 were a carpenter, then x_8 is reading a book can be inferred via the universal biconditional elimination rule. For all x_8, if x_8 reads a book, then x_8 is a carpenter can be inferred via the universal biconditional elimination rule.