avoid obsolete Sign.read_prop;

tuned proofs -- avoid implicit prems;

fixed imports path;

tuned proofs -- avoid open cases;

function package: using the names of the equations as case names turned out to be impractical => disabled

avoid name clashes when generating code for union, inter

oops -- avoid vacous goal message; tuned messages;

tuned messages; tuned;

avoid "import" as identifier, which is a keyword in Alice;

tuned presentation;

avoid implicit use of prems; tuned proofs;

where/of: do not allow schematic variables here!

removed unused read_termTs_schematic, read/cert_vars_legacy, add_fixes_legacy; discontinued legacy_intern_skolem, gen_read';

discontinued legacy vars;