A friendly iteration forcing that the four cardinal characteristics of E can be pairwise different
Abstract
Let E be the σ-ideal generated by the closed measure zero sets of reals. We use an ultrafilter-extendable matrix iteration of ccc posets to force that, for E, their associated cardinal characteristics (i.e.\ additivity, covering, uniformity and cofinality) are pairwise different.
0
Turn this paper into a lesson
ArcXiv compiles a structured reading guide from this paper's metadata: plain-English importance, contributions, prerequisite concepts, which sections to read first, flashcards, and a quiz. Grounded in the abstract, never invented.