On a result of G. D. Birkhoff on linear differential systems
On a result of G. D. Birkhoff on linear differential systems
We give a simple example to show that a result on the equivalent singular points of systems of ordinary linear differential equations due to G. D. Birkhoff [3; 5, needs amendment.In matrix notation, in which Y, P, etc. denote nXn matrix-valued functions of a complex variable z, this result is …