Fig. 3From: Comparative genomics meets topology: a novel view on genome median and halving problems a) A collection \(\mathcal {P}\) of three polygons (two 4-gons and one 8-gon) oriented clockwise, where blue dashed edges represent a matching on the sides in \(\mathcal {P}\). b) The embedded graph G Σ with v=5 vertices, e=8 edges, f=3 faces, and g(Σ)=1 (i.e., Σ is a torus) resulted from the oriented gluing of \(\mathcal {P}\) Back to article page