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 if x_7 were a politician, then x_7 is working. For all x_7, if x_7 works, then x_7 is reading a book. For all x_7, if x_7 were a taxi driver, then x_7 is working. For all x_7, x_7 is a politician or x_7 is a taxi driver.
For all x_7, if x_7 were a taxi driver, then x_7 is reading a book can be inferred via the universal transitivity rule. There is at least one x_7 for which if x_7 were a politician, then x_7 is reading a book can be inferred via the existential transitivity rule. There is at least one x_7 for which x_7 will work can be inferred via the existential disjunction elimination rule.