Generalized Von Neumann Universe and Non-Well-Founded Sets
Eugene Zhang
TL;DR
The paper proposes the total universe, an enlarged von Neumann hierarchy that explicitly includes non-well-founded sets (infinitons, semi-infinitons, quasi-infinitons) via limits of finite structures and formulas. It develops a rigorous framework using limit theories (both in infinitary logics and set-theoretic language) to define infinitely generated sets and their types, then constructs the total universe T with new inf-generation operators and a spectrum of power-set operations. EZF, an extended ZF-like theory, is introduced to accommodate both WF and NWf sets, and the Russell paradox is shown to be avoidable within this framework by distinguishing infiniton classes and their hierarchies. Overall, the work argues that Regularity is not necessary for consistency with ZF and that the total universe provides a robust, paradox-free foundation integrating non-well-founded sets with well-founded ones. The approach offers a new, rigorous route to study non-well-founded phenomena using limits, spectrum-based construction, and an extended axiomatic base.
Abstract
In this paper, a generalized version of the von Neumann universe known as the total universe is proposed to formally introduce non-well-founded sets that include infinitons, semi-infinitons and quasi-infinitons in Russell's paradox. All three infinitons are part of infinitely generated sets that are generators of non-well-founded sets. Combining the well-founded sets with the non-well-founded sets, the total universe is a model of ZF minus the axiom of regularity and free of Russell's paradox. The axiom of regularity is invalid in defining well-founded sets and wrong in any system consistent with ZF set theory.
