Now showing items 1-4 of 4

    • Binary relations coming from solutions of functional equations: orderings and fuzzy subsets 

      Campión Arrastia, María Jesús Upna; Miguel Turullols, Laura de Upna; García Catalán, Olga Raquel Upna; Induráin Eraso, Esteban Upna; Abrísqueta Usaola, Francisco Javier Upna (World Scientific Publishing Company, 2017)   Artículo / Artikulua  OpenAccess
      We analyze the main properties of binary relations, defined on a nonempty set, that arise in a natural way when dealing with real-valued functions that satisfy certain classical functional equations on two variables. We ...
    • Pointwise aggregation of maps: its structural functional equation and some applications to social choice theory 

      Miguel Turullols, Laura de Upna; Campión Arrastia, María Jesús Upna; Candeal, Juan Carlos; Induráin Eraso, Esteban Upna; Paternain Dallo, Daniel Upna (Elsevier, 2017)   Artículo / Artikulua  OpenAccess
      We study a structural functional equation that is directly related to the pointwise aggregation of a finite number of maps from a given nonempty set into another. First we establish links between pointwise aggregation and ...
    • Semicontinuous planar total preorders on non-separable metric spaces 

      Campión Arrastia, María Jesús Upna; Candeal, Juan Carlos; Induráin Eraso, Esteban Upna (The Korean Mathematical Society, 2009)   Artículo / Artikulua  OpenAccess
      We prove that every non-separable connected metric space can be endowed with a total preorder that is order-isomorphic to a nonrepresentable subset of the lexicographic plane and semicontinuous with respect to the metric topology.
    • Weightable quasi-metrics related to fuzzy sets 

      Campión Arrastia, María Jesús Upna; García Catalán, Olga Raquel Upna; Induráin Eraso, Esteban Upna; Valero, Óscar (Hacettepe University (Turquía), 2018)   Artículo / Artikulua  OpenAccess
      We show that the definition of a fuzzy set is directly related to the existence of a weightable quasi-metric on a universe. This relationship is also explored in terms of functional equations coming either from the membership ...