tuned whitespace;

tuned;

tuned, following be8c0e039a5e;

more markup for syntax consts;

proper flags (amending 1319c729c65d): abbrevs are allowed, free variables are disallowed;

Some tidying

merged

Tidied some messy old proofs

merged

more markup for syntax consts;

more markup for syntax consts;

clarified concrete syntax;

more accurate markup (amending 43c4817375bf): only consider primitive syntax consts, avoid extra Markup.intensify e.g. due to "\<^const>Pure.all_binder";

more concrete syntax and more checks;

clarified signature: more operations;

support for syntax const dependencies, with minimal integrity checks;

tuned;

clarified markup: more uniform treatment of parse/print phase;

tuned;

clarified markup: more uniform;

tuned signature: separate markup vs. extern;

clarified signature;

tuned: prefer configuration options via context;

tuned;