anchor: Dutch and Hieronymus Bosch (c. 1450 1516), whom the Spanish call El Bosco, has three masterpieces in the Prado, including a large triptych called The Garden of Earthly Delights.
positive: The Garden of Earthly Delights is by El Bosco.
negative: None of Bosch's masterpieces in the Prado are triptychs.