• and denote the singular value decomposition of G(jw0) by
•
• where r is the rank of G(jw0) and ui ,vi have unit length.
• If w0< ¥, write v1(jw0) as
•
•                                          
• where aiÎR is such that qiÎ(-p,0]. Now let 0 £ bi £ ¥  be such that
•
• (with bi=¥  if qi=0 ) and let  f  be given by
•
•