Mapping fiber, loop and suspension graphs in naive discrete homotopy theory

Discrete homotopy theory or A-homotopy theory is a combinatorial homotopy theory defined on graphs, simplicial complexes and metric spaces, reflecting information about their connectivity. The purpose of the present paper is to further understanding of the similarities between the A-homotopy and ordinary homotopy theories. More precisely, we define the notion of a mapping fiber in the category of graphs and study its basic properties, providing non-compatibility with projection.