Translate the following inference to logic notation: David is a bartender or Robert is an electrician. David is a bartender if and only if Robert is playing a game. For all x, if x_10 were an electrician, then x_10 is playing a game. Therefore Robert is playing a game.
p or P(a). p <-> Q(a). forall x: P(x) -> Q(x). Therefore Q(a).