Theory of (q 1, q 2)-quasimetric spaces and coincidence points

We introduce (q1, q2)-quasimetric spaces and examine their properties. Covering mappings between (q1, q2)-quasimetric spaces are investigated. Sufficient conditions for the existence of a coincidence point of two mappings acting between (q1, q2)-quasimetric spaces such that one is a covering mapping and the other satisfies the Lipschitz condition are obtained. © 2016, Pleiades Publishing, Ltd.