On fuzzy and interval-valued fuzzy subhyperlattice

We introduced the notions of fuzzy subhyperlattice and fuzzy ideal, listed equivalent conditions of fuzzy subhyperlattice and fuzzy ideal, concluded that the two different definitions of fuzzy ideal are equivalent, proved that the Cartesian product of two fuzzy subhyperlattices is a fuzzy subhyperlattice too and gave an example to show that the product of two fuzzy ideals may not be a fuzzy ideal. Then we generalized our results to interval-valued fuzzy version.