A fixed point theorem of Banach--Caccioppoli type on a class of generalized metric spaces

We give a fixed point theorem related to the contraction mapping principle of Banach and Caccioppoli; here we have considered generalized metric spaces, that is metric spaces with the triangular inequality replaced by similar ones which involve four or more points instead of three. At the end of the paper an example is provided to show the improvement of our result with respect to the classical one.