tuned signature;

proper treatment of position constraints;

more liberal ast matching, notably for case-translations in HOLCF that operate on logical consts rather than syntax consts;

more parser markup, based on position constraints for logical mixfix syntax;

more concise representation of term positions;

more robust;

tuned signature;

tuned comments;

misc tuning and clarification;

clarified concrete vs. abstract syntax: avoid translations on logical consts;

misc tuning and clarification;

clarified markers for syntax consts: avoid overlap with logical consts;

update ci mail address;

minor performance tuning;

notable performance tuning (amending a59d9b81be24 and 8976c5bc9e97): avoid costly could_beta_eta_contract, which traverses the whole term; always use Item_Net.retrieve instead, but on frozen TVars/Vars to enforce matching instead of unification;

tuned;

clarified signature;

tuned whitespace;

support multiple positions (non-empty list);

more robust syntax translation;

clarified concrete vs. abstract syntax;

more inner-syntax markup;

clarified concrete vs. abstract syntax;

clarified concrete vs. abstract syntax;