Numercial should be "Numerical".

Keith Dr. Keith M. Briggs Senior Mathematician, Complexity Research, BT Exact http://more.btexact.com/people/briggsk2/ (internet) http://research.btexact.com/teralab/keithbriggs.html (BT intranet) phone: +44(0)1473 work: 641 911 home: 610 517 fax: 642 161 mail: Keith Briggs, Polaris 134, Adastral Park, Martlesham, Suffolk IP5 3RE, UK