Intertwined Synchronized Systems

An asymmetric-RLL$(d_1,k_1,d_0,k_0)$ system is a subshift of $\{0,1\}^{\mathbb Z}$ with run of $1$ and $0$ restricted to $S=[d_1,k_1]\subseteq\mathbb N_{0}=\mathbb N\cup\{0\}$ and $S'=[d_0,k_0]\subseteq\mathbb N_{0}$ respectively. We extend this concept to the case when $S$ and $S'$ are arbitrary subsets of $\mathbb N_{0}$ and we call it a $(S,S')$-gap shift. Moreover, for $i=1,2$, if $X_{i}$ is a synchronized system generated by $V_{i}=\{v^{i}\alpha_{i}:\alpha_i v^{i}\alpha_i\in\mathcal B(X_i),\alpha_i\not\subseteq v^{i}\}$ where $\alpha_i$ is a synchronizing word for $X_i$, then a natural generalization of $(S,S')$-gap shifts is a coded system $Z$ generated by $\{v^{1}\alpha_1 v^{2}\alpha_2:v^{i}\alpha_i\in V_{i}, i=1,2\}$ and called the intertwined system. We investigate the dynamical properties of $Z$ with respect to $X_1$ and $X_2$.