premise: In the Oratory of the Crib (Oratorio del Presepio) are the moving 13th-century sculptures of Joseph, the Three Kings, the ox, and the ass, by Arnolfo di Cambio (Mary and the child Jesus are 16th-century additions).
hypothesis: Joseph, the Three Kings, the ox, and the ass appear in sculpture form in di Cambio's Oratory of the Crib.