Logic in State Space Model

Hi,

I got a problem when I was trying to call ss(A,B,C,D) function.

And my matrix has logic inside with respect to one of the states like this

A = [ 0 1 0; 0 0 1; -1*(x2>3)+3*(x2<=3) 2 -1]

How do I deal with that? Since I should define the state first. Or my problem is how should I define a state before calling state space model?

Thanks a lot!!