460 BELL SYSTEM TECHNICAL JOURNAL 



we ha\e 



Pi 



«! = 



12 



2 r p,z 7'^P^'^ -1 

 ao=_^_ p,-9p, ^^^ hPs I 



i+p.,zL ' 'i-\-p.,z^ '(i+p.zyj 



ai = Y^^{^[_-^Pia,Z+2P,a,a,Z,Zr^ 



+ ^[P6-3P7aiZ + 3P8arZ--P9ai-^Z^]), 



+ i^r -3P7a2Z+6P8aia,Z--3P9ai-a2Z-^1 



+ i|-[Pio-4PnaiZ+6Pioai2Z-^-4Pi3ai"'Z^+Puai^Z^]) 



^""" 14-P Z \W I ~2P4a4Z+2P5(aia4Z-+aoa3Z-) 1 

 + ^ [-3P7a3Z + 3P8(ao2Z- + 2aia3Z2) 



- Pgia iZao-Z'- + 2aoa3Z- + 2a ia.:^Z' + a i^aaZ^) ] 

 + r|-r-4Pua2Z+12Pi,aiaoZ--12Pi3ai-a2Z'^ + 4P,4ai''a2Zn 



+ J5- [P]5-5Pi6aiZ + lOPuai^Z'^ - lOPigOi^Z^ 



+ 5Pi9ai^Z^-P2oai'Zs)]' 



