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Discussiones Mathematicae General Algebra and Applications 22(2) (2002) 161-166
DOI: https://doi.org/10.7151/dmgaa.1055

AN INVERSE MATRIX OF AN UPPER TRIANGULAR MATRIX CAN BE LOWER TRIANGULAR

Waldemar Houbowski

Institute of Mathematics
Silesian University of Technology
Kaszubska 23, 44-101 Gliwice, Poland
e-mail: wholub@polsl.gliwice.pl

Abstract

In this note we explain why the group of n×n upper triangular matrices is defined usually over commutative ring while the full general linear group is defined over any associative ring.

Keywords: upper tringular invertible matrix, group of matrices, Dedekind-finite ring.

2000 Mathematics Subject Classification: 20H25.

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