3 papers
math.CT2019
Facets of congruence distributivity in Goursat categories
Marino Gran, Diana Rodelo, Idriss Tchoffo Nguefeu
We give new characterisations of regular Mal'tsev categories with distributive lattice of equivalence relations through variations of the so-called Triangular Lemma and Trapezoid L…
math.CT2018
Variations of the Shifting Lemma and Goursat categories
Marino Gran, Diana Rodelo, Idriss Tchoffo Nguefeu
We prove that Mal'tsev and Goursat categories may be characterised through stronger variations of the Shifting Lemma, that is classically expressed in terms of three congruences $R…
math.CT2018
Goursat completions
Diana Rodelo, Idriss Tchoffo Nguefeu
We characterize categories with weak finite limits whose regular completions give rise to Goursat categories.