What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all y_3, y_3 is a writer. There is at least one y_3 for which y_3 is an astronaut or y_3 is happy. For all y_3, y_3 is not an astronaut.
There is at least one y_3 for which y_3 is happy.