@highergeometer @johncarlosbaez Adams apparently stumbled across the similar problem while at St John's Cambridge in the early 1970s. There was a staircase being renovated and furniture was moved into a room at the top of the stair to get it out of the way. After the staircase was finished, the sofas would no longer fit down the stairs no matter how you manipulated them, so the furniture was stuck in those upstairs rooms for decades.