Just want to ask my friends if there's anyone of you have heard before about the labels as follows:
Mathematical exception(mx(t)) - central value (x(t)-mx(t) - unit exchange(Rxx(t',t''))-Dxx(t',t'')......

We are taking this metterial which called (systems theory) at our department of electronic engineering,it's fulled of mathematical relations...
I wonder if the resources of this material is available on the internet :?

Thanks in advance!!