What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_13, if x_13 were a taxi driver, then x_13 is an office clerk. There is at least one x_13 for which x_13 will read a book and x_13 is happy. For all x_13, if x_13 were a politician, then x_13 is an office clerk. For all x_13, if x_13 reads a book, then x_13 is a taxi driver.
For all x_13, if x_13 reads a book, then x_13 is an office clerk. There is at least one x_13 for which x_13 will read a book. There is at least one x_13 for which x_13 is happy.