Question about strong regularity of (parametric) interval matrices

[skalna <skalna@xxxxxxxxxx>]

Dear Members of Interval Community,

I have the following question. Most of papers on solving interval linear
systems says that interval matrix is strongly regular if
\rho(|(mid(A))^{-1}rad([A])|)<1.
or equivalently if
[B]=mid(A))^{-1}[A] is regular.
But we can also post-multiply the matrix, and it is probable that the 
matrix
[B] will not be regular, but the matrix
[C]=[A}A^{-1} will be regular.
So, shouldn't the definition of strong regularity of interval matrices 
be changed?
I am in fact more interested in parametric interval matrices, but 
parametric
matrices are strictly connected with interval matrices.

Best regards,
  Iwona Skalna

--
 ___ ____ __ __
| _ |   _|  |  | | Iwona Skalna                            |
|   |  | |     | | Department of Applied Computer Science  |
|_|_|____|__|__| | ul. Gramatyka 10, 30-067 Kraków, Polska |