On the rotation distance of graphs

Abstract Let ( x , y ) be an edge of a graph G . Then the rotation of ( x , y ) about x is the operation of removing ( x , y ) from G and inserting ( x , y ′) as an edge, where y ′ is a vertex of G . The rotation distance between graphs G and H is the minimum number of rotations necessary to transform G into H . Lower and upper bounds are given on the rotation distance of two graphs in terms of their greatest common subgraphs and their partial rotation link of largest cardinality. We also propose some extermal problems for the rotation distance of trees.