  Following the development of fuzzy logic theory by Lotfi Zadeh, its
applications were investigated by researchers in different fields. Presenting
and working with uncertain data is a complex problem. To solve for such a
complex problem, the structure of relationships and operators dependent on such
relationships must be repaired. The fuzzy database has integrity limitations
including data dependencies. In this paper, first fuzzy multivalued dependency
based semantic proximity and its problems are studied. To solve these problems,
the semantic proximity's formula is modified, and fuzzy multivalued dependency
based on the concept of extension of semantic proximity with \alpha degree is
defined in fuzzy relational database which includes Crisp, NULL and fuzzy
values, and also inference rules for this dependency are defined, and their
completeness is proved. Finally, we will show that fuzzy functional dependency
based on this concept is a special case of fuzzy multivalued dependency in
fuzzy relational database.
