  The explicite formulas for Mobius function and some other important elements
of the incidence algebra of an arbitrary cobweb poset are delivered. For that
to do one uses Kwasniewski's construction of his cobweb posets . The digraph
representation of these cobweb posets constitutes a newly discovered class of
orderable DAG's named here down KoDAGs with a kind of universality now being
investigated. Namely cobweb posets' and thus KoDAGs's defining di-bicliques are
links of any complete relations' chains.
