code: @Override
  	public void propagate(int evtmask) throws ContradictionException {
  		for (int i = 0; i < n; i++) {
  			for (int j = 0; j < n; j++) {
  				if (matrix[i][j].getLB() == 1) {
  					g.enforceArc(i, j, this);
  				} else if (matrix[i][j].getUB() == 0) {
  					g.removeArc(i, j, this);
  				}
  			}
  		}
  	}
docs: ***********************************************************************************