Coanalytic families of functions
Abstract
For Van Douwen families, maximal families of eventually different permutations and maximal ideal independent families we show that the existence of a 12 family implies the existence of a 11 family of the same size. We also prove a similar, but slightly weaker result for generating sets of cofinitary groups.
0
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.