A note on the paper 'Combination of interval-valued fuzzy set and soft set' [Comput. Math. Appl. 58 (2009) 521–527]

Yang (the second author of this paper) et al. (2009) [3] established the distributive law of interval-valued fuzzy soft sets. In this article, it is pointed that it is not true in general. But, in order to establish the distributive law of interval-valued fuzzy soft sets, more general notions than interval-valued fuzzy soft sets and interval-valued fuzzy soft equal are considered. Using such notions, the generalized distributive law of interval-valued fuzzy soft sets is established.