Strong and ultra separation axioms on fuzzy bitopological spaces

Given a fuzzy bitopological space (X, tau(1), tau(2)), we introduce a new notion of fuzzy pairwise separation axioms by using the family of its level bitopologies l alpha(tau(1)), l alpha(tau(2)), alpha is an element of [0,1). We prove that these concepts are good extension and we compare them with its corresponding FPTi (Kandil and El-Shafee, 1991) and FPT*(i) (Abu Safiya et al., 1994) (i = 0, 1,2, 3, 4), respectively. We show that these notions are not equivalent and we give a number of examples which illustrate this fact. (C) 1999 Elsevier Science B.V. All rights reserved.