Editing Zermelo set theory (section)

{{Short description|System of mathematical set theory}}
{{more footnotes|date=April 2018}}

'''Zermelo set theory''' (sometimes denoted by '''Z'''<sup>'''-'''</sup>), as set out in a seminal paper in 1908 by [[Ernst Zermelo]], is the ancestor of modern [[Zermelo–Fraenkel set theory]] (ZF) and its extensions, such as [[von Neumann–Bernays–Gödel set theory]] (NBG).  It bears certain differences from its descendants, which are not always understood, and are frequently misquoted.  This article sets out the original [[axiom]]s, with the original text (translated into English) and original numbering.