http://reply.papertrans.cn/1/5/406/406-21.png
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Submitted on: 06 December 2000.
Revised on: 22 January 2001.
Accepted on: 05 February 2001.
___________________ACTA NUMERICA---CAMBRIDGE UNIV PRESS
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http://reply.papertrans.cn/1/5/406/406-29.png
Submitted on: 30 June 2014.
Revised on: 20 September 2014.
Accepted on: 17 October 2014.
___________________ACTA NUMERICA---CAMBRIDGE UNIV PRESS