\(v\left(\text{Lab}\ 1\right)=\ n_{1}\ f_{1},\ v\left(\text{La}b\ 2\right)=n_{2}\ f_{2}\ ,\ldots..,v\left(\text{Lab}\ 25\right)=\ n_{25}\ f_{25}\) \(\left(1\right)\)
\(v\left(Lab1\ \cup Lab\ 2\right)=\ f_{12}\left(n_{12}\right),\ v\left(Lab\ 2\ \cup Lab\ 3\right)=f_{23}\left(n_{23}\right)\ ,\ldots\),
\(v\left(Lab\ 24\ \cup Lab\ 25\right)=\ f_{24\ 25}\left(n_{24\ 25}\right)\)
\(\vdots\)
\(v\left(Lab1\ \cup Lab\ 2\ \cup\ldots\ \cup Lab\ 25\right)=\ f_{1\ 2\ldots 25}\ (n_{1\ 2\ 3\ldots 25})\)