
 On the Shape of the Symmetric, Persymmetric and SkewSymmetric Solution Set  Alefeld, Kreinovich, Mayer (ResearchIndex) (Site not responding. Last check: 20071009) 
  We show that in each orthant the sets Ssym, Sper and S skew, respectively, are the intersection of S with sets the boundaries of which are quadrics. 
  Alefeld, V. Kreinovich, and G. Mayer, "The Shape of the Symmetric, Persymmetric, and SkewSymmetric Solution Set", SIAM Journal on Matrix Analysis and Applications (SIMAX), 1997, Vol. 
  6 the Symmetric and Unsymmetric Solution Set of Interval Syste.. 
 citeseer.ist.psu.edu /559868.html (468 words) 
