What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all y_4, if y_4 plays tennis, then y_4 is an astronaut. For all y_4, if y_4 were an astronaut, then y_4 is playing tennis. Linda is a carpenter or Robert is an astronaut. For all y_4, y_4 will not play tennis. Linda is not a carpenter or Patricia is playing squash.
Robert is an astronaut or Patricia is playing squash. If Robert were happy, then Linda is a carpenter. For all y_4, y_4 is not an astronaut. For all y_4, y_4 will play tennis if and only if y_4 is an astronaut. For all y_4, y_4 is an astronaut if and only if y_4 will play tennis.