activity
20172024
most citedA special class of congruences on -frames

5 citations · 10 across the 6 of their papers we have counts for

collaborators

7 papers

math.GN2024

Sequences suffice for pointfree uniform completions

Graham Manuell

Completions of metric spaces are usually constructed using Cauchy sequences. However, this does not work for general uniform spaces, where Cauchy filters or nets must be used inste…

math.GN2023

Pointfree topology and constructive mathematics

Graham Manuell

The constructive approach to mathematics has the advantage that witnesses can be extracted from statements of existence and theorems can be unwound to give algorithms. Even better,…

math.RA2022

Congruence frames of frames and -frames

Graham Manuell

We describe the congruence lattices of frames and -frames. We look at the role that congruence biframes play in the category of strictly zero-dimensional biframes and discuss so…

math.GN2021★ 1 cited

Uniform locales and their constructive aspects

Graham Manuell

Much work has been done on generalising results about uniform spaces to the pointfree context. However, this has almost exclusively been done using classical logic, whereas much of…

math.GN2019★ 3 cited

The congruence biframe as a quasi-uniform bicompletion

Graham Manuell

Künzi and Ferrario have shown that a space is sober if and only if it is bicomplete in the well-monotone quasi-uniformity. We prove a pointfree version of this result: a stri…

math.GN2017★ 1 cited

Strictly zero-dimensional biframes and a characterisation of congruence frames

Graham Manuell

Strictly zero-dimensional biframes were introduced by Banaschewski and Brümmer as a class of strongly zero-dimensional biframes including the congruence biframes. We consider the c…

math.RA2017★ 5 cited

A special class of congruences on -frames

Graham Manuell

Madden has shown that in contrast to the situation with frames, the smallest dense quotient of a -frame need not be Boolean. We characterise these so-called d-reduced -frames…