Título: Sandwich-type characterization of completely regular spaces
Autor: Gutiérrez García, Javier; Kubiak, Tomasz
Resumen: [EN] All the higher separation axioms in topology, except for complete regularity, are known to have sandwich-type characterizations. This note provides a characterization of complete regularity in terms of inserting a continuous real-valued function. The known fact that each continuous real valued function on a compact subset o fa Tychonoff space has a continuous extension to the whole space is obtained as a corollary.