Find all keys in the following relations:
R(A, B, C, D, E, F) ℉ = { A → BC BD → EF F → A } 

Obviously: the following facts are true
A → A B → B C → C D → D E → E F → F 
The set of functional dependencies ℉ are the added benefits :
℉ = { A → BC BD → EF F → A } 
Problem statement:

How do you go set up your minimal menu ?
Step 1: compute closure of all functional dependencies in ℉:

Step 2:
Example:

Done !!!
