Translate the following inference to logic notation: If Richard makes tea, then Michael is driving a car. If Elisabeth were an astronaut, then Thomas is climbing a mountain. If Thomas climbs a mountain, then Richard is making tea. If Michael drives a car, then Elisabeth is an astronaut. Therefore Michael is driving a car if and only if Richard is making tea.
p -> q. r -> s. s -> p. q -> r. Therefore q <-> p.