4 papers
Antichain of ordinals in intuitionistic set theory
Shuwei Wang
In classical set theory, the ordinals form a linear chain that we often think of as a very thin portion of the set-theoretic universe. In intuitionistic set theory, however, this i…
An equiconsistency proof for
Shuwei Wang
In many axiomatic set theories, Gödel's constructible universe is known as an inner model, that is, a definable class satisfying the same axioms (and containing the same ordin…
Some notes on plump ordinals
Shuwei Wang
In this exposition, we attempt to formalise a treatment of Paul Taylor's notion of plump ordinals in weak intuitionistic axiomatic set theories such as IKP. We will explore basic p…
An ordinal analysis of CM and its extensions
Shuwei Wang
In arXiv:0905.1675, Nik Weaver proposed a novel intuitionistic formal theory of third-order arithmetic as a formalisation of his philosophical position known as mathematical concep…