•  33
    We characterize the sets of all Π2 and all equation image theorems of IΠ−1 in terms of restricted exponentiation, and use these characterizations to prove that both sets are not deductively equivalent. We also discuss how these results generalize to n > 0. As an application, we prove that a conservation theorem of Beklemishev stating that IΠ−n + 1 is conservative over IΣ−n with respect to equation image sentences cannot be extended to Πn + 2 sentences. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, We…Read more
  •  26
    Maximum Schemes in Arithmetic
    Mathematical Logic Quarterly 40 (3): 425-430. 1994.
    In this paper we deal with some new axiom schemes for Peano's Arithmetic that can substitute the classical induction, least-element, collection and strong collection schemes in the description of PA
  •  21
    Induction, minimization and collection for Δ n+1 (T)–formulas
    Archive for Mathematical Logic 43 (4): 505-541. 2004.
    For a theory T, we study relationships among IΔ n +1 (T), LΔ n+1 (T) and B * Δ n+1 (T). These theories are obtained restricting the schemes of induction, minimization and (a version of) collection to Δ n+1 (T) formulas. We obtain conditions on T (T is an extension of B * Δ n+1 (T) or Δ n+1 (T) is closed (in T) under bounded quantification) under which IΔ n+1 (T) and LΔ n+1 (T) are equivalent. These conditions depend on Th Πn +2 (T), the Π n+2 –consequences of T. The first condition is connected …Read more
  •  20
    On the quantifier complexity of Δ n+1 (T)– induction
    Archive for Mathematical Logic 43 (3): 371-398. 2004.
    In this paper we continue the study of the theories IΔ n+1 (T), initiated in [7]. We focus on the quantifier complexity of these fragments and theirs (non)finite axiomatization. A characterization is obtained for the class of theories such that IΔ n+1 (T) is Π n+2 –axiomatizable. In particular, IΔ n+1 (IΔ n+1 ) gives an axiomatization of Th Π n+2 (IΔ n+1 ) and is not finitely axiomatizable. This fact relates the fragment IΔ n+1 (IΔ n+1 ) to induction rule for Δ n+1 –formulas. Our arguments, invo…Read more
  •  18
    Aproximaciones al concepto de vulnerabilidad desde la bioética: una revisión integradora
    with Carlos Alberto Fernández-Silva, Carla Ximena Bittner Hofmann, and Claudio Radiel Mancilla Mancilla
    Persona y Bioética 25 (2): 2522-2522. 2022.
    A corpus of 60 articles published in Spanish, English, and Portuguese was analyzed to account for the integrative literature review on the concept of vulnerability from bioethics, identifying the following thematic trends: risk, susceptibility, autonomy, and culture in people and communities. The methodological approach has been mainly qualitative. We found that the disciplines that most addressed the concept belong to the human and social sciences. The authors recommend conducting studies of th…Read more
  •  17
    On axiom schemes for T-provably $${\Delta_{1}}$$ Δ 1 formulas
    Archive for Mathematical Logic 53 (3-4): 327-349. 2014.
    This paper investigates the status of the fragments of Peano Arithmetic obtained by restricting induction, collection and least number axiom schemes to formulas which are Δ1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\Delta_1}$$\end{document} provably in an arithmetic theory T. In particular, we determine the pr…Read more
  •  11
    Engaging people with lived experience in the grant review process
    with Katherine Rittenbach, Candice G. Horne, Terence O’Riordan, Allison Bichel, Nicholas Mitchell, and Frank P. MacMaster
    BMC Medical Ethics 20 (1): 1-5. 2019.
    People with lived experience are individuals who have first-hand experience of the medical condition being considered. The value of including the viewpoints of people with lived experience in health policy, health care, and health care and systems research has been recognized at many levels, including by funding agencies. However, there is little guidance or established best practices on how to include non-academic reviewers in the grant review process. Here we describe our approach to the inclu…Read more
  • Herve pasqua, maître Eckhart. Le procès de l'un (review)
    Acta Philosophica 16 (2). 2007.