Around cofin
Logic
2014-04-23 v2
Abstract
We show the consistency of "there is a nice sigma --ideal I on the reals with add(I)= omega_1 which cannot be represented as the union of a strictly increasing sequence of length omega_1 of sigma-subideals". This answers a question by Borodulin-Nadzieja and Glab.
Cite
@article{arxiv.1304.5683,
title = {Around cofin},
author = {Andrzej Roslanowski and Saharon Shelah},
journal= {arXiv preprint arXiv:1304.5683},
year = {2014}
}