Take the following as truth: Begun in 1060, the Duomo San Martino, has a Pisan-style three-storied facade with a Descent from the Crosecarved by Nicola Pisano over the north door.
Then the following statement: "Nicola Pisano was the only artist hired for beautifying the Duimo San Martino." is true, false, or inconclusive?
Answer: Inconclusive