Text: Vaclav Havel was in New York in the spring of 1968, participated in the student strike at Columbia, joined Alexander Dubcek in the short-lived liberal uprising in Prague that summer, and became the president of Czechoslovakia in 1990.
Entailment: Vaclav Havel, the president of Czechoslovakia in 1990, had been in New York in 1968.
Contradiction: Vaclav Havel had never been to the United States before becoming president of Czechoslovakia.