even more permissive approximation of master_dir, which is only required to access external resources ('uses' etc.);

back to implicit commit via isabelle-process -- save image only once (cf. 181b91e1d1c1);

proper axiomatization of "mem" -- do not leave it formally unspecified;

simplified Pure bootstrap -- separate pure_setup.ML was required for Alice/ML at some point;

more casual exit back to ML toplevel, to accomodate commit in SML/NJ which continues at the saved point;

obsolete;