  We introduce the concept of quasi-coincidence of a fuzzy interval value with
an interval valued fuzzy set. By using this new idea, we introduce the notions
of interval valued $(\in,\ivq)$-fuzzy filters of pseudo $BL$-algebras and
investigate some of their related properties. Some characterization theorems of
these generalized interval valued fuzzy filters are derived. The relationship
among these generalized interval valued fuzzy filters of pseudo $BL$-algebras
is considered. Finally, we consider the concept of implication-based interval
valued fuzzy implicative filters of pseudo $BL$-algebras, in particular, the
implication operators in Lukasiewicz system of continuous-valued logic are
discussed.
