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 plays a game, then x is making tea. Mary is sad or Joseph is not playing a game. For all x, if x makes tea, then x is playing a game.
If Joseph plays a game, then Mary is sad. For all x, x will play a game if and only if x will make tea. For all x, x will make tea if and only if x will play a game.