Independence of graph changes from Roseman moves

A graph change of a virtual broken surface diagram is a modification preserving the Gauss code of the double-point curves that either passes a double-point curve through another curve or itself, or changes the framing induced by the intersecting surfaces. Roseman moves and virtual Roseman moves are the standard diagrammatic moves for surface links and virtual surface links. Graph-change independence conjecture. Graph changes cannot in general be obtained using Roseman moves and virtual Roseman moves. This claim motivates including graph changes as an additional equivalence in the diagrammatic description of virtual $2$-links.