enter image description hereI am unable to understand the graph operation defined in the following paper https://www.sciencedirect.com/science/article/pii/S0972860017301706.
Can someone kindly explain how the 1st graph operation is defined and how can we draw the graph?
I am attaching the screenshot where I am having trouble understanding. How is this new operation is defined and does it make sense?
How is this a generalization of Indu-Bala Product as referred in the paper? Please help
If someone can explain using any example for the graphs $G_1,G_2,G_3$ ,I will be grateful.