Is this database 3NF or BCNF?

Question

I have this table that the rules are: A student is examined in a discipline and obtains a position on the class list. It is known that two students cannot obtain the same position in the same subject. Is this a 3NF database or BCNF, i cant have a 100% sure answer to this

Answer 1

-- Student STUDENT examined in course COURSE
-- obtained position POSITION on class list.
--
test {STUDENT, COURSE, POSITION}
 KEY {STUDENT, COURSE}
 KEY {COURSE, POSITION}

Nontrivial FDs:

{STUDENT, COURSE}   --> {POSITION}
{COURSE, POSITION}  --> {STUDENT}

Use this as a quick check for NF:

---------------------------------------
For each nontrivial |
    FD X --> Y      |
at least one holds  | 2NF   3NF   BCNF
---------------------------------------
X is a superkey        ✔     ✔     ✔

Y is a subkey          ✔     ✔

X is not a subkey      ✔
---------------------------------------

FD X --> Y is trivial iff Y ⊆ X

For both nontrivial FDs X is a superkey; BCNF.