Talk:Kripke–Platek set theory with urelements

From Wikipedia, the free encyclopedia

Mathematics Portal This article is within the scope of WikiProject Mathematics, which collaborates on articles related to mathematics.
Mathematics rating:	Start Class	Low Priority	Field: Foundations, logic, and set theory
Please update this rating as the article progresses, or if the rating is inaccurate. Click to show/hide comments. Please add to or update the comments to suggest improvements to the article. Geometry guy 21:25, 9 July 2007 (UTC)

In what way does it differ from just ZF without the axiom of infinity ? --195.93.102.71 22:41, 26 Apr 2005 (UTC)Mike (Michel Josserand)

It lacks for instance axioms for power sets, an infinite set, or choice. Bgohla 22:48, 2005 May 3 (UTC)

If there's no infinity, the power set and the choice hold. I realize that the axiom of foundation is stated differently from it is in ZF but apparently ZF without infinity can be derived from KPU. Can KPU be derived from ZF minus infinity, in other words, does ZF actually preclude urelements? - Michel42