What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all y, y is an astronaut if and only if y is sad. There is at least one y for which if y were a soldier, then y is an astronaut. For all y, if y were an astronaut, then y is a soldier. For all y, y is not a soldier.
For all y, y is not an astronaut. There is at least one y for which y is a soldier if and only if y is an astronaut. There is at least one y for which y is an astronaut if and only if y is a soldier. For all y, if y were an astronaut, then y is sad. For all y, if y were sad, then y is an astronaut.