Restricted block duplicate graph

Restricted block duplicate graph --- ограниченный блоково дублированный граф.

A restricted block duplicate (RBD) graph is a graph obtained by adding zero or more true twins to each vertex of a block graph [math]\displaystyle{ B }[/math], subject to the restriction that a cut-vertex belonging to three or more blocks of [math]\displaystyle{ B }[/math] receive at most one true twin.