BCNF decomposition

Question

The redundancy in the set of relation that has been arised after decomposing relation R into BCNF is more than zero but less than 3NF decomposition if multivalued dependencies are considered

why and how?? if possible explanation with an example

Answer 1

I think multivalued dependency arise in 4NF form, and because every BCNF is in 3NF the redundancy in the relation after decomposing into BCNF will be less than 3NF from but more than 0(Multivalued).

Comments

i guess since BCNF must necessarily have superkey in LHS of the functional dependency

and suppose multivalued attribute is considered as phone number

one person can have 2 phone numbers

therefore there will be redundancy

but less than 3NF

is my logic valid ?