The concept of Kuratowski pair is one possible way of encoding the concept of an ordered pair in material set theory (say in the construction of Cartesian products): A pair of the form is represented by the set of the form .
The main point is to cook up a definition whereby if and only if and , where set equality may be verified via the axiom of extensionality. Obviously many such definitions are possible, but Kuratowski’s is a simple one.
Last revised on May 8, 2017 at 20:06:34. See the history of this page for a list of all contributions to it.