What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_8, x_8 will play tennis if and only if x_8 is fast. There is at least one x_8 for which if x_8 were sad, then x_8 is playing tennis. For all x_8, x_8 is fast or x_8 is sad. For all x_8, if x_8 were fast, then x_8 is playing tennis.
There is at least one x_8 for which x_8 will play tennis. For all x_8, if x_8 plays tennis, then x_8 is fast. For all x_8, if x_8 were fast, then x_8 is playing tennis.