Applied Categorical Structures

, Volume 19, Issue 2, pp 469–487

Insertion of Continuous Real Functions on Spaces, Bispaces, Ordered Spaces and Pointfree Spaces—A Common Root

  • Maria João Ferreira
  • Javier Gutiérrez García
  • Jorge Picado

DOI: 10.1007/s10485-009-9209-0

Cite this article as:
Ferreira, M.J., Gutiérrez García, J. & Picado, J. Appl Categor Struct (2011) 19: 469. doi:10.1007/s10485-009-9209-0


We characterize normal and extremally disconnected biframes in terms of the insertion of a continuous real function in between given lower and upper semicontinuous real functions and show this to be the common root of several classical and new insertion results concerning topological spaces, bitopological spaces, ordered topological spaces and locales.


FrameLocaleLocalic real functionInsertion theoremBiframeNormal biframeExtremally disconnected biframeBitopological spaceOrdered topological space

Mathematics Subject Classifications (2000)


Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Maria João Ferreira
    • 1
  • Javier Gutiérrez García
    • 2
  • Jorge Picado
    • 1
  1. 1.CMUC, Department of MathematicsUniversity of CoimbraCoimbraPortugal
  2. 2.Departamento de Matemáticas-Matematika SailaUniversidad del País Vasco-Euskal Herriko UnibertsitateaBilbaoSpain