Text: Imagine that in 1987, within an effort to estimate the extent of tax revenues lost or delayed from the failure of businesses to file returns, the General Accounting Office examined revenue shortfalls to individual states.
Entailment: In 1987 an effort to estimate tax revenues lost or delayed was made, and was caused by the failure of business to file returns.
Contradiction: The General Accounting Office made no effort at all to estimate tax revenue lost.