6 papers
Hyper-MacNeille Completions of Heyting algebras
John Harding, Frederik Lauridsen
A Heyting algebra is supplemented if each element has a dual pseudo-complement , and a Heyting algebra is centrally supplement if it is supplemented and each supplement is…
Orthogeometries and AW*-algebras
John Harding, Bert Lindenhovius
Based on results of Harding, Heunen, Lindenhovius and Navara, (2019), we give a connection between the category of AW*-algebras and their normal Jordan homomorphisms and a category…
Topos quantum theory with short posets
John Harding, Chris Heunen
Topos quantum mechanics, developed by Isham et. al., creates a topos of presheaves over the poset V(N) of abelian von Neumann subalgebras of the von Neumann algebra N of bounded op…
A topos view of the type-2 fuzzy truth value algebra
John Harding, Carol Walker
It is known that fuzzy set theory can be viewed as taking place within a topos. There are several equivalent ways to construct this topos, one is as the topos of étalé spaces over…
The Convolution Algebra
John Harding, Carol Walker, Elbert Walker
For a complete lattice and a relational structure , we introduce the convolution algebra . This algebra consists of the lattice $L^X…
Wigner's theorem for an infinite set
John Harding
It is well known that the closed subspaces of a Hilbert space form an orthomodular lattice. Elements of this orthomodular lattice are the propositions of a quantum mechanical syste…