Summary
- moved over material from AFP; most importantly on algebraic numbers and algebraically closed fields
- tuned;
- removed unused/obsolete material: some of it was motivated by Isabelle/MMT (e.g. f150253cb201), but is superseded by AFP metadata (TOML);
- clarified signature;
- clarified modules: more official Sessions.notable_groups;
- tuned
- merged
- An assortment of new material, mostly due to Manuel