λ-cluster point

Last-modified: 2011-12-27 (火) 22:56:23

Definition

  • Let S be a subset of a topological space (X, τ). A point x in a topological space (X, τ) is called a λ-cluster point of S if every λ-open set U of X containing x such that imgtex.fcgi?%5bres=100%5d%7b%5c%5b%20S%5ccap%20U%5cneq%5cemptyset%20%5c%5d%7d%25.png .

Reference

  • Caldas Miguel, Jafari Saeid, On some low separation axioms via λ-open and λ-closure operator., Rend. Circ. Mat. Palermo (2) 54 (2005), no. 2, 195–208.