On two epireflective subcategories of the category of 2T0–fuzzy bitopological spaces

The motivation for the present work is provided by Giuli and Salbany's work on the category BTOP0 of T0-bitopological spaces wherein they identified a cogenerator Q and a closure operator and used these to obtain, among other things, two interesting epireflective subcategories of BTOP0 consisting of objects which they referred to as ‘absolutely 2T0-closed' and ‘bisober' respectively. Moreover, the first such subcategory was also shown by them to be the epireflective hull of Q in BTOP0. We show here that almost a perfectly analogous programme can be carried out within the category BFTS0 of 2T0-fuzzy bitopological spaces after identifying a key cogenerator in BFTS0. Keywords: 2T0-fuzzy bitopological space, absolutely 2T0-closed fuzzy bitopological space, sober fuzzy bitopological space, closure operator, epireflective subcategory, epireflective hullQuaestiones Mathematicae 23(2000), 163–17