Synthesis sets for $H^{\infty} + C$ Pamela GorkinRaymond Mortini 46J15bounded analytic functoinsclosed idealssynthesis setsDouglas algebrasBlaschke products Indiana University Mathematics Journal 2000 text pdf 10.1512/iumj.2000.49.1718 10.1512/iumj.2000.49.1718 en Indiana Univ. Math. J. 49 (2000) 287 - 310 state-of-the-art mathematics http://iumj.org/access/