Superstability of the functional equation related to distance measures

Young Whan Lee, Gwang Hui Kim
2015 Journal of Inequalities and Applications  
The functional equation related to a distance measure f (pr, qs) + f (ps, qr) = f (p, q)f (r, s)
doi:10.1186/s13660-015-0880-4 fatcat:j3q5wpo3cbf33bka67pqscdhwm