activity
20192026
most citedAn alternative approach to the calculation of fundamental groups based on labeled natural deduction

3 citations · 3 across the 7 of their papers we have counts for

collaborators

8 papers

math.AC2026

A Prime-Generated Formalization of Nagata's Factoriality Theorem in Lean 4

Arthur F. Ramos, Ruy J. G. B. de Queiroz, Anjolina G. de Oliveira

We present a Lean 4 Mathlib formalization of Nagata's factoriality theorem: if R is a noetherian domain and S <= R is a prime-generated submonoid such that S^{-1}R is a UFD, then R…

cs.LO2025

The Seifert-van Kampen Theorem via Computational Paths: A Formalized Approach to Computing Fundamental Groups

Arthur F. Ramos, Tiago M. L. de Veras, Ruy J. G. B. de Queiroz +1

The Seifert-van Kampen theorem computes the fundamental group of a space from the fundamental groups of its constituents. We develop a modular SVK framework within the setting of c…

cs.LO2025

A Modular Lean 4 Framework for Confluence and Strong Normalization of Lambda Calculi with Products and Sums

Arthur Ramos, Anjolina Oliveira, Ruy de Queiroz +1

We present Metatheory, a comprehensive library for programming language foundations in Lean 4. The library features a modular framework for proving confluence of abstract rewriting…

cs.LO2025

Computational Paths Form a Weak ω-Groupoid

Arthur F. Ramos, Tiago M. L. de Veras, Ruy J. G. B. de Queiroz +1

Lumsdaine (2010) and van den Berg-Garner (2011) proved that types in Martin-Löf type theory carry the structure of weak ω-groupoids. Their proofs, while foundational, rely on abstr…

cs.LO2025

Formalizing Computational Paths and Fundamental Groups in Lean

Arthur F. Ramos, Anjolina G. de Oliveira, Ruy J. G. B. de Queiroz +1

Computational paths treat propositional equality as explicit paths built from labelled deduction steps and rewrite rules. This view originates in work by de Queiroz and collaborato…

math.HO2025

Meaning as Use, Application, Employment, Purpose, Usefulness

Ruy J. G. B. de Queiroz

Arising from the whole body of Wittgenstein's writings is a picture of a (not necessarily straight, linear, but admittedly tireless) journey to come to terms with the mechanics of…

math.HO2025

From the Notebooks to the Investigations and Beyond

Ruy J. G. B. de Queiroz

The use of the open and searchable Wittgenstein's Nachlass (The Wittgenstein Archives at the University of Bergen (WAB)) has proved instrumental in the quest for a common thread of…

cs.LO2019★ 3 cited

An alternative approach to the calculation of fundamental groups based on labeled natural deduction

Tiago M. L. de Veras, Arthur F. Ramos, Ruy J. G. B. de Queiroz +1

In this work, we use a labelled deduction system based on the concept of computational paths (sequence of rewrites) as equalities between two terms of the same type. We also define…