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: There is at least one x_7 for which x_7 will read a book or x_7 is not an office clerk. For all x_7, x_7 will drive a car or x_7 is an office clerk. For all x_7, x_7 will drive a car if and only if x_7 will read a book.
There is at least one x_7 for which if x_7 were an office clerk, then x_7 is reading a book can be inferred via the existential rewriting rule. For all x_7, if x_7 drives a car, then x_7 is reading a book can be inferred via the universal biconditional elimination rule. For all x_7, if x_7 reads a book, then x_7 is driving a car can be inferred via the universal biconditional elimination rule.