557 



together we get the final equation in X for g of the type 



s [(*':)' w-] g : + 2 [x f : x r i ,] 9 i + & c . = 2 [x? <]. 



The coefficients in the final equations for g and h are the same. 



In the same way the final equations in Y and Z for g or A,"' are 

 formed. 



