$G$-colorings of posets, coverings and presentations of the fundamental   group
  We introduce the notion of a coloring of a poset, which consists of a labeling of the edges in its Hasse diagram by elements in a given group $G$. We use $G$-colorings to describe the covering maps of posets and present a new method based on colorings to obtain concrete and simple presentations of the fundamental group of polyhedra. 
Jonathan Ariel Barmak and Elias Gabriel Minian
math.AT math.CO