Abstract

 Richard S. Varga and Alan Krautstengl, On Gergorin-type problems and ovals of Cassini, ETNA, 8(1999), 15-20. MR 99k.15020. Zbl. 0927.15008. 

Abstract. Recently, two Gergorin-type matrix questions were raised. These are answered here, using ovals of Cassini.

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