... a hinge of G.If|B[x,y ]|≥3,then the set of edges of G having x and y as ends, together with the edges of ˆG of the form e2B,forB ∈B2[x,y ], induces a cleavage unit of G. Furthermore, ... B1,B2, ,Brbe the blocks of H containing the edges of P . There are no other blocks of H.If any Bihas two or more edges, then let u, v be the attachments of Biin G.Thereis a [u, v]-bridge ... andhaving the specified finite set of vertices on the boundary of the same face, in the specificcyclic order.One way of approaching this technical lemma is to first prove it for 3-connected graphs (the...