I learned this many years ago as the Borromean food problem, after Borromean rings: https://en.wikipedia.org/wiki/Borromean_rings https://en.wikipedia.org/wiki/

I learned this many years ago as the Borromean food problem, after Borromean rings: https://en.wikipedia.org/wiki/Borromean_rings https://en.wikipedia.org/wiki/Borromean_rings