by Tadeusz Litak
Reference:
Tadeusz Litak: Some notes on the superintuitionistic logic of chequered subsets of ${\sf R}^\infty$, In Bulletin of the Section of Logic, 33(2), pp. 81–86, 2004. The paper studies superintuitionistic version of the logic of chequered subsets introduced by Johan van Benthem, Guram Bezhanishvili and Mai Gehrke. It is observed that this logic possesses
the disjunction property, contains the Scott axiom, fails to contain the
Kreisel-Putnam axiom and is not structurally complete. It is also a sublogic of the Medvedev logic
ML.
Very interesting
follow-up results have been obtained by Gaelle Fontaine and Timofei Shatrov. The latter claimed to have settled negatively the issue of finite axiomatizably of Cheq; however, to the best of my knowledge, this has never been published. The local copy is slightly extended; in particular, the
proof of main theorem is hopefully more readable: [local copy]
Bibtex Entry:
@article{Litak04:bsl,
title={Some notes on the superintuitionistic logic of chequered subsets of ${\sf R}^\infty$},
author={Litak, Tadeusz},
journal={Bulletin of the Section of Logic},
volume={33},
number={2},
pages={81--86},
url = {https://arxiv.org/abs/1808.06393},
ALTurl = {http://www.filozof.uni.lodz.pl/bulletin/pdf/33_2_2.pdf},
year={2004},
comment = {<div class="abstract"> The paper studies superintuitionistic version of the logic of chequered subsets introduced by <a href="http://dx.doi.org/10.1023/B\%3ASTUD.0000009564.00287.16">Johan van Benthem, Guram Bezhanishvili and Mai Gehrke</a>. It is observed that this logic possesses
the disjunction property, contains the Scott axiom, fails to contain the
Kreisel-Putnam axiom and is not structurally complete. It is also a sublogic of the Medvedev logic
ML. </div> <div class="textleft">
Very interesting
follow-up results have been obtained by <a href="http://www.aiml.net/volumes/volume6/Fontaine.ps">Gaelle Fontaine</a> and <a href="http://atlas-conferences.com/cgi-bin/abstract/caug-46">Timofei Shatrov</a>. The latter claimed to have settled negatively the issue of finite axiomatizably of Cheq; however, to the best of my knowledge, this has never been published. The local copy is slightly extended; in particular, the
proof of main theorem is hopefully more readable: </div> <a href="http://www8.cs.fau.de/~litak/papers/euclidean2018.pdf"> [local copy] </a>}
}