Inhomogeneous self-affine carpets J. Fraser Indiana University Mathematics Journal 2016 text pdf 10.1512/iumj.2016.65.5903 10.1512/iumj.2016.65.5903 en Indiana Univ. Math. J. 65 (2016) 1547 - 1566 state-of-the-art mathematics http://iumj.org/access/