A new diagonal separation property in the category of
locales
Jorge Picado, CMUC, Department of
Mathematics, University of Coimbra, Portugal
SAMS Subject Classification Number: 13, 4
Recall that the Hausdorff property of a topological space
Given a property relevant in the category in question (typically of a
topological nature), an object
In the context of locales there are the important properties of
fittedness and fitness [5]. A sublocale of a locale is
fitted if it is an intersection of open ones and a
locale is fit if each of its sublocales is fitted.
Since the intersection
Taking into account the fact that the subcategory of fit locales is
closed under products and subobjects, we have an immediate observation
that fitness implies
References
[1] I. Arrieta, J. Picado and A. Pultr, A new diagonal separation and its relations with the Hausdorff property, Appl. Categ. Structures 30 (2022) 247–263.
[2] M.M. Clementino, E. Giuli and W. Tholen, A functional approach to general topology, in: Categorical Foundations, Encyclopedia Math. Appl., vol. 97, Cambridge Univ. Press, Cambridge, 2004, pp. 103–163.
[3] M.M. Clementino, J. Picado and A. Pultr, The other closure and complete sublocales, Appl. Categ. Structures 26 (2018) 891–908.
[4] A. Joyal and M. Tierney, An extension of the Galois theory of Grothendieck, Mem. Amer. Math. Soc. 51 (1984), no. 309.
[5] J. Picado and A. Pultr, Separation in point-free topology, Birkhäuser-Springer, Cham, 2021.
[6] J. Picado and A. Pultr, On equalizers in the category of locales, Appl. Categ. Structures 29 (2021) 267–283.