bsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</font><font face="Symbol" color="#000100" size="3">f
</font><font face="Arial" color="#000100" size="2"><sub>ijk
</sub></font><font face="Arial" color="#000100" size="3"> = e
</font><font face="Symbol" color="#000100" size="3"><sup>a
</sup></font><font face="Arial" color="#000100" size="2">k
</font><font face="Arial" color="#000100" size="3"> + 
</font><font face="Symbol" color="#000100" size="3">b
</font><font face="Arial" color="#000100" size="2"><sub>ik
</sub></font><f