Dear Kokovidis and Medical, thank you very much, I changed k[s] to k[ss] as your directed, then maple worked very well.

Best Regards!

Thank you very much! Those days I asked some similar questions and get the answer effectively.

Thanks for your attention.I will try to learn more about maple.It is powerful.

Best regards,

Wang

Thank you very much! Those days I asked some similar questions and get the answer effectively.

Thanks for your attention.I will try to learn more about maple.It is powerful.

Best regards,

Wang