Sentence: Yet in Judd's stack of galvanized-iron boxes , all of the units are identical; they are set on the wall and separated, so that none is subordinated to another's weight (and also so that the space around them plays a role in the work equivalent to theirs); and their regular climb -- each of the twelve boxes is nine inches high, and they rest nine inches apart -- suggests an infinitely extensible series, denying the possibility of a crowning summit.
Entities: entity1: boxes; entity2: stack
Relationship: Member-Collection