This Paper is to introduce and define a new class of open set in
bitopological space called pre-Nα-open as generalized of pre-α-open in topological
space , and we study their basic properties
Authors: Thinh D. Nguyen
Comments: 2 Pages.
We show that if one has ever loved reading Prasolov’s books, then one can move on reading our recent article  and several words following to deduce that partitioning a graph into triangles is not an easy problem.