Abstract
Similarly as the sobriety is essential for representing continuous maps as frame homo-morphisms, also other separation axioms play a basic role in expressing topological phenomena in frame language. In particular,T D is equivalent with the correctness of viewing subspaces as sublocates, or with representability of open or closed maps as open or closed homomorphisms. A weaker separation axiom is equivalent with an algebraic recognizability whether the intersection of a system of open sets remains open or not. The role of sobriety is also being analyzed in some detail.
Similar content being viewed by others
References
C.E. Aull and W.J. Thron: Separation axioms betweenT 0 andT 1,Indag. Math. 24 (1962), 26–37.
B. Banaschewski and A. Pultr: Variants of openness,J. Appl. Categorical Structures (forthcoming).
A. Grothendieck and J. Dieudonné: Élements de géometrie algébrique, tome I: le language de schémas, I.H.E.S. Publ. Math. no. 4, 1960.
R.-E. Hoffmann: On weak Hausdorff spaces,Archiv der Math. (Basel)32 (1979), 487–504.
R.-E. Hoffmann:Projective Sober Spaces, Continuous lattices (Proc. Bremen 1979), Lecture Notes in Math.871 (1981), 125–158.
J.R. Isbell: Uniform spaces, Math. Surveys No. 12, Amer. Math. Soc., Providence, R.I., 1964.
P.T. Johnstone:Stone Spaces, Cambridge University Press, Cambridge, 1982.
P.T. Johnstone:Factorization Theorems for Geometric Morphisms II, Categorical Aspects of Topology and Analysis, Lecture Notes in Math.915, 216–233.
A. Pultr and A. Tozzi: Notes on Kuratowski-Mrówka theorems in point-free context,Cahiers de Top. et Géom. Diff. Cat. XXXIII-1 (1992), 3–14.
R. Sikorski: Remarks on some topological spaces of high power,Fund. Math. 37 (1950), 125–136.
W.J. Thron: Lattice-equivalence of topological spaces,Duke Mat. J. 29 (1962), 671–679.
Author information
Authors and Affiliations
Additional information
In honour of Nico Pumplün on the occasion of his 60th birthday
The support of the Italian C.N.R. is gratefully acknowledged.
Partial financial support of the Italian M.U.R.S.T. is gratefully acknowledged.
Rights and permissions
About this article
Cite this article
Pultr, A., Tozzi, A. Separation axioms and frame representation of some topological facts. Appl Categor Struct 2, 107–118 (1994). https://doi.org/10.1007/BF00878507
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00878507