What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_7, x_7 is not a scientist. For all x_7, x_7 is a scientist if and only if x_7 will play a game. There is at least one x_7 for which x_7 is a mechanic or x_7 is a police officer. For all x_7, if x_7 were a mechanic, then x_7 is playing a game.
For all x_7, if x_7 were a scientist, then x_7 is playing a game. For all x_7, if x_7 plays a game, then x_7 is a scientist. For all x_7, x_7 will not play a game.