# Sh:485

• Abraham, U., & Shelah, S. (2002). Coding with ladders a well ordering of the reals. J. Symbolic Logic, 67(2), 579–597.
• Abstract:
Any model of ZFC + GCH has a generic extension (made with a poset of size \aleph_2) in which the following hold: MA + 2^{\aleph_0}=\aleph_2+ there exists a \Delta^2_1-well ordering of the reals. The proof consists in iterating posets designed to change at will the guessing properties of ladder systems on \omega_1. Therefore, the study of such ladders is a main concern of this article.
• Version 2001-03-24_10 (30p) published version (20p)
Bib entry
@article{Sh:485,
author = {Abraham, Uri and Shelah, Saharon},
title = {{Coding with ladders a well ordering of the reals}},
journal = {J. Symbolic Logic},
fjournal = {The Journal of Symbolic Logic},
volume = {67},
number = {2},
year = {2002},
pages = {579--597},
issn = {0022-4812},
mrnumber = {1905156},
mrclass = {03E35 (03E50)},
doi = {10.2178/jsl/1190150099},
note = {\href{https://arxiv.org/abs/math/0104195}{arXiv: math/0104195}},
arxiv_number = {math/0104195}
}