Graph minor theory

Graph minor theory is a significant area of research within graph theory that deals with the concept of "minors." A graph \( H \) is said to be a minor of a graph \( G \) if \( H \) can be formed from \( G \) by a series of operations that include: 1. **Deleting vertices**: Removing a vertex and its associated edges. 2. **Deleting edges**: Removing edges between vertices.