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_10 for which if x_10 were an office clerk, then x_10 is a doctor. For all x_10, x_10 is an office clerk or x_10 will not read a book. For all x_10, if x_10 were a doctor, then x_10 is playing tennis. For all x_10, if x_10 plays tennis, then x_10 is reading a book.
For all x_10, if x_10 were a doctor, then x_10 is reading a book can be inferred via the universal transitivity rule. There is at least one x_10 for which if x_10 were an office clerk, then x_10 is playing tennis can be inferred via the existential transitivity rule. For all x_10, if x_10 reads a book, then x_10 is an office clerk can be inferred via the universal rewriting rule.