Translate the following inference to logic notation: David is not an electrician. For all x, x_11 is an artist if and only if x_11 is an electrician. If Patricia plays tennis, then Richard is an astronaut. Patricia is playing tennis. Therefore Richard is an astronaut and David is not an artist.
~P(a). forall x: Q(x) <-> P(x). p -> q. p. Therefore q and ~Q(a).