Can anyone assist me to find out what should be the ILP formulation of a case when I try to label vertices by say 0$0$, 1$1$ and 2$2$ and want the subgraph of graph (V,E)$(V,E)$ made by same vertex set but edge set being those which have atleastat least one end point as 1$1$ or 2$2$, to be connected. I don't need objective functions, just want to know how to show this as a constraint.
