/m + 7 n + 7\ |----- - -----|*m*n \ m n / ------------------- 2 2 m - n
/7 + m -7 - n\ m*n*|----- + ------| \ m n / -------------------- 2 2 m - n
/7 + m 7 + n\ m*n*|----- - -----| \ m n / ------------------- 2 2 m - n
m*n*((7.0 + m)/m - (7.0 + n)/n)/(m^2 - n^2)
m*(-7 - n) + n*(7 + m) ---------------------- 2 2 m - n
n*(7 + m) - m*(7 + n) --------------------- 2 2 m - n
/m + 7 n + 7\ m*n*|----- - -----| \ m n / ------------------- 2 2 m - n