Unitary Triangularization of a Nonsymmetric Matrix

A method for the inversion of a nonsymmetric matrix has been in use at ORNL and has proved to be highly stable numerically but to require a rather large number of arithmetic operations, including a total of N(N-1)/2 square roots. This note points out that the same result can be obtained with fewer arithmetic operations, and, in particular, for inverting a square matrix of order N, at most 2(N-1) square roots are required. For N > 4, this is a savings of (N-4)(N-1)/4 square roots. (T.B.A.)