What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is snowing or Robert is sleeping. Linda is not playing a game. If Linda plays a game, then Robert is sleeping. If Robert sleeps, then Linda is playing a game. It is not snowing or Mary is making tea.
Robert is not sleeping. Robert is sleeping or Mary is making tea. Linda is playing a game if and only if Robert is sleeping. Robert is sleeping if and only if Linda is playing a game.