*Definition [#tf920cbe]
-A subset S of a topological space (X,τ) is called a λ-closed if S = L∩F, where L is a [[Λ-set]] and F is closed.

*Reference [#w57a3789]
-Arenas Francisco G., Dontchev Julian, Ganster Maximilian, ''On λ-sets and the dual of generalized continuity.'', Questions Answers Gen. Topology 15 (1997), no. 1, 3-13.