In an infinite-dimensional space V, as used in functional analysis, the flag idea generalises to a subspace nest, namely a collection of subspaces of V that is a total order for inclusion and which further is closed under arbitrary intersections and closed linear spans. See nest algebra.
Read more about this topic: Flag (linear Algebra)
Famous quotes containing the word nest:
“How then can we account for the persistence of the myth that inside the empty nest lives a shattered and depressed shell of a woman—a woman in constant pain because her children no longer live under her roof? Is it possible that a notion so pervasive is, in fact, just a myth?”
—Lillian Breslow Rubin (20th century)