Text: The piazza's 17th-century sunken-boat-shaped marble fountain, Fontana della Barcaccia, is by the great Bernini's father.
Entailment: The great Bernini's father is known to be the creator of the piazza's 17th-century sunken boat shaped marble fountain.
Contradiction: The Fontana della Barcaccia was created by the great Bernini's son.