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arXiv · 0905.0526

Nonproper Products

Andrzej Roslanowski·Saharon Shelah·Otmar Spinas
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Abstract

We show that there exist two proper creature forcings having a simple (Borel) definition, whose product is not proper. We also give a new condition ensuring properness of some forcings with norms.

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BibTeXRIS

Andrzej Roslanowski, Saharon Shelah, Otmar Spinas. 2011-08-16. Nonproper Products. https://doi.org/10.1112/blms%2Fbdr094

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