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, if x_8 were a doctor, then x_8 is reading a book. For all x_8, if x_8 plays tennis, then x_8 is cooking. For all x_8, if x_8 writes a letter, then x_8 is reading a book. For all x_8, x_8 will play tennis. For all x_8, x_8 will write a letter or x_8 is a doctor.
For all x_8, x_8 will cook can be inferred via the universal modus ponens rule. For all x_8, x_8 will read a book can be inferred via the universal disjunction elimination rule.