“…The motivation for our study comes from discrete dynamical systems, where one is concerned with the iterates of a map f : X → X. In our more general context, given any collection F of self maps of X, we define a composition sequence generated by F to be a sequence (F n ), where F n = f 1 f 2 · · · f n and f i ∈ F. Composition sequences generated by sets of analytic self maps of complex domains have received much attention; see, for example, [2,6,13,14]. There has been particular focus on generating sets composed of Möbius transformations that map a disc within itself -see [1,4,5,12,15,16] -partly because of applications to the theory of continued fractions.…”