Stability test of linear time-delay systems

This program is easy to test the stability of a linear time-delay system.

In our book [1], we provide a simple approach to test the stability of linear time-delay system. We have following test theorem.
Theorem 1 [1]: Give a linear time-delay system,
dx(t)/dt=Ax(t)+Bx(t-h)
the system is stable, if
(1) A is Hurwitz stable,
(2) A+B*exp(-jwh) is Hurwitz stable.
where h is a time-delay, it is a fixed constant, h>=0, and w is angle frequency.
This program realized Theorem 1, it is easy to test the stability of a linear time-delay system,if we know the matrices A and B, and time-delay h.
[1] Yang Xiao, Yingkang Zhang, Multidimensional Signal Processing and
Multidimensional Systems, Publishing House of Electronics Industry,Beijing, 2011.