What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x, if x were happy, then x is a police officer. For all x, x will write a letter or x is not a police officer. For all x, if x writes a letter, then x is happy.
For all x, if x writes a letter, then x is a police officer. For all x, if x were a police officer, then x is writing a letter.