Text: Ghirlandaio, master teacher of Leonardo da Vinci, decorated the Sassetti Chapel (far right of the high altar) with frescoes of St. Francis, and the Adoration of the Shepherds on the altar is considered his masterpiece.
Entailment: The Adoration of the Shepherds is Ghirlandaio's masterpiece.
Contradiction: Ghirlandaio was a jealous competitor of Leonardo da Vinci.