Text: Instead of our regular class work, let's go outside under the big, old dead elm and show a filmstrip, i.e., let's quote a few highlights from Tim Weiner's dark and charming New York Times obit titled Sidney Gottlieb, 80, Dies, Took LSD to CIA, an account of the man who ran MKUltra, a project that dosed unsuspecting Americans with hallucinogenic drugs for charity.
Entailment: Let's skip classwork today and go outside to watch a movie by the elm tree.
Contradiction: Since it's raining outside, we should stay in and do our regular classwork.