“…For example, one can program the robots so that, starting from an initial configuration without any holes, they can self-reconfigure into a line containing all the robots, without ever breaking the connectivity of the system [17,6]. However, it has been shown and proven [7,5] that the number of all possible configurations of modular robots increases drastically as the number of *This work has been supported by the EIPHI Graduate School (contract "ANR-17-EURE-0002") † All authors are with Univ. Bourgogne Franche-Comté, FEMTO-ST Institute, CNRS, 1 cours Leprince-Ringuet, 25200, Montbéliard, France.…”