2 problems

Angle-labeling characterization of essentially 3-connected maps. The map $M$ admits an edge, $\mathbb{N}^*$-vertex, $\mathbb{N}^*$-face angle labeling if and only if it is essentia…

Angle-labeling characterization of triangulations. The map $M$ admits a 1-edge, $\mathbb{N}^*$-vertex, 1-face angle labeling if and only if $M$ is a triangulation.