What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x, x is a mechanic. If Charles were a nurse, then Karen is not a mechanic. For all x_7, x_7 is a nurse if and only if x_7 will read a book.
For all x_7, if x_7 were a nurse, then x_7 is reading a book. For all x_7, if x_7 reads a book, then x_7 is a nurse.