diff --git a/src/Pure/Isar/spec_rules.ML b/src/Pure/Isar/spec_rules.ML
--- a/src/Pure/Isar/spec_rules.ML
+++ b/src/Pure/Isar/spec_rules.ML
@@ -1,187 +1,187 @@
 (*  Title:      Pure/Isar/spec_rules.ML
     Author:     Makarius
 
 Rules that characterize specifications, with optional name and
 rough classification.
 
 NB: In the face of arbitrary morphisms, the original shape of
 specifications may get lost.
 *)
 
 signature SPEC_RULES =
 sig
   datatype recursion =
     Primrec of string list | Recdef | Primcorec of string list | Corec | Unknown_Recursion
   val recursion_ord: recursion ord
   val encode_recursion: recursion XML.Encode.T
   datatype rough_classification = Equational of recursion | Inductive | Co_Inductive | Unknown
   val rough_classification_ord: rough_classification ord
   val equational_primrec: string list -> rough_classification
   val equational_recdef: rough_classification
   val equational_primcorec: string list -> rough_classification
   val equational_corec: rough_classification
   val equational: rough_classification
   val is_equational: rough_classification -> bool
   val is_inductive: rough_classification -> bool
   val is_co_inductive: rough_classification -> bool
   val is_relational: rough_classification -> bool
   val is_unknown: rough_classification -> bool
   val encode_rough_classification: rough_classification XML.Encode.T
-  type spec =
+  type spec_rule =
    {pos: Position.T,
     name: string,
     rough_classification: rough_classification,
     terms: term list,
     rules: thm list}
-  val get: Proof.context -> spec list
-  val get_global: theory -> spec list
-  val dest_theory: theory -> spec list
-  val retrieve: Proof.context -> term -> spec list
-  val retrieve_global: theory -> term -> spec list
+  val get: Proof.context -> spec_rule list
+  val get_global: theory -> spec_rule list
+  val dest_theory: theory -> spec_rule list
+  val retrieve: Proof.context -> term -> spec_rule list
+  val retrieve_global: theory -> term -> spec_rule list
   val add: string -> rough_classification -> term list -> thm list -> local_theory -> local_theory
   val add_global: string -> rough_classification -> term list -> thm list -> theory -> theory
 end;
 
 structure Spec_Rules: SPEC_RULES =
 struct
 
 (* recursion *)
 
 datatype recursion =
   Primrec of string list | Recdef | Primcorec of string list | Corec | Unknown_Recursion;
 
 val recursion_index =
   fn Primrec _ => 0 | Recdef => 1 | Primcorec _ => 2 | Corec => 3 | Unknown_Recursion => 4;
 
 fun recursion_ord (Primrec Ts1, Primrec Ts2) = list_ord fast_string_ord (Ts1, Ts2)
   | recursion_ord (Primcorec Ts1, Primcorec Ts2) = list_ord fast_string_ord (Ts1, Ts2)
   | recursion_ord rs = int_ord (apply2 recursion_index rs);
 
 val encode_recursion =
   let open XML.Encode in
     variant
      [fn Primrec a => ([], list string a),
       fn Recdef => ([], []),
       fn Primcorec a => ([], list string a),
       fn Corec => ([], []),
       fn Unknown_Recursion => ([], [])]
   end;
 
 
 (* rough classification *)
 
 datatype rough_classification = Equational of recursion | Inductive | Co_Inductive | Unknown;
 
 fun rough_classification_ord (Equational r1, Equational r2) = recursion_ord (r1, r2)
   | rough_classification_ord cs =
       int_ord (apply2 (fn Equational _ => 0 | Inductive => 1 | Co_Inductive => 2 | Unknown => 3) cs);
 
 val equational_primrec = Equational o Primrec;
 val equational_recdef = Equational Recdef;
 val equational_primcorec = Equational o Primcorec;
 val equational_corec = Equational Corec;
 val equational = Equational Unknown_Recursion;
 
 val is_equational = fn Equational _ => true | _ => false;
 val is_inductive = fn Inductive => true | _ => false;
 val is_co_inductive = fn Co_Inductive => true | _ => false;
 val is_relational = is_inductive orf is_co_inductive;
 val is_unknown = fn Unknown => true | _ => false;
 
 val encode_rough_classification =
   let open XML.Encode in
     variant
      [fn Equational r => ([], encode_recursion r),
       fn Inductive => ([], []),
       fn Co_Inductive => ([], []),
       fn Unknown => ([], [])]
   end;
 
 
 (* rules *)
 
-type spec =
+type spec_rule =
  {pos: Position.T,
   name: string,
   rough_classification: rough_classification,
   terms: term list,
   rules: thm list};
 
-fun eq_spec (specs: spec * spec) =
+fun eq_spec (specs: spec_rule * spec_rule) =
   (op =) (apply2 #name specs) andalso
   is_equal (rough_classification_ord (apply2 #rough_classification specs)) andalso
   eq_list (op aconv) (apply2 #terms specs) andalso
   eq_list Thm.eq_thm_prop (apply2 #rules specs);
 
-fun map_spec_rules f ({pos, name, rough_classification, terms, rules}: spec) : spec =
+fun map_spec_rules f ({pos, name, rough_classification, terms, rules}: spec_rule) : spec_rule =
   {pos = pos, name = name, rough_classification = rough_classification, terms = terms,
     rules = map f rules};
 
 structure Rules = Generic_Data
 (
-  type T = spec Item_Net.T;
+  type T = spec_rule Item_Net.T;
   val empty : T = Item_Net.init eq_spec #terms;
   val extend = I;
   val merge = Item_Net.merge;
 );
 
 
 (* get *)
 
 fun get_generic imports context =
   let
     val thy = Context.theory_of context;
     val transfer = Global_Theory.transfer_theories thy;
     fun imported spec =
       imports |> exists (fn thy => Item_Net.member (Rules.get (Context.Theory thy)) spec);
   in
     Item_Net.content (Rules.get context)
     |> filter_out imported
     |> (map o map_spec_rules) transfer
   end;
 
 val get = get_generic [] o Context.Proof;
 val get_global = get_generic [] o Context.Theory;
 
 fun dest_theory thy = rev (get_generic (Theory.parents_of thy) (Context.Theory thy));
 
 
 (* retrieve *)
 
 fun retrieve_generic context =
   Item_Net.retrieve (Rules.get context)
   #> (map o map_spec_rules) (Thm.transfer'' context);
 
 val retrieve = retrieve_generic o Context.Proof;
 val retrieve_global = retrieve_generic o Context.Theory;
 
 
 (* add *)
 
 fun add name rough_classification terms rules lthy =
   let
     val pos = Position.thread_data ();
     val thms0 = map Thm.trim_context (map (Drule.mk_term o Thm.cterm_of lthy) terms @ rules);
   in
     lthy |> Local_Theory.declaration {syntax = false, pervasive = true}
       (fn phi => fn context =>
         let
           val (terms', rules') =
             map (Thm.transfer (Context.theory_of context)) thms0
             |> Morphism.fact phi
             |> chop (length terms)
             |>> map (Thm.term_of o Drule.dest_term)
             ||> map Thm.trim_context;
         in
           context |> (Rules.map o Item_Net.update)
             {pos = pos, name = name, rough_classification = rough_classification,
               terms = terms', rules = rules'}
         end)
   end;
 
 fun add_global name rough_classification terms rules =
   (Context.theory_map o Rules.map o Item_Net.update)
     {pos = Position.thread_data (), name = name, rough_classification = rough_classification,
       terms = terms, rules = map Thm.trim_context rules};
 
 end;
diff --git a/src/Pure/Thy/export_theory.ML b/src/Pure/Thy/export_theory.ML
--- a/src/Pure/Thy/export_theory.ML
+++ b/src/Pure/Thy/export_theory.ML
@@ -1,447 +1,446 @@
 (*  Title:      Pure/Thy/export_theory.ML
     Author:     Makarius
 
 Export foundational theory content and locale/class structure.
 *)
 
 signature EXPORT_THEORY =
 sig
   val setup_presentation: (Thy_Info.presentation_context -> theory -> unit) -> unit
   val export_body: theory -> string -> XML.body -> unit
 end;
 
 structure Export_Theory: EXPORT_THEORY =
 struct
 
 (* approximative syntax *)
 
 val get_syntax = Syntax.get_approx o Proof_Context.syn_of;
 fun get_syntax_type ctxt = get_syntax ctxt o Lexicon.mark_type;
 fun get_syntax_const ctxt = get_syntax ctxt o Lexicon.mark_const;
 fun get_syntax_fixed ctxt = get_syntax ctxt o Lexicon.mark_fixed;
 
 fun get_syntax_param ctxt loc x =
   let val thy = Proof_Context.theory_of ctxt in
     if Class.is_class thy loc then
       (case AList.lookup (op =) (Class.these_params thy [loc]) x of
         NONE => NONE
       | SOME (_, (c, _)) => get_syntax_const ctxt c)
     else get_syntax_fixed ctxt x
   end;
 
 val encode_syntax =
   XML.Encode.variant
    [fn NONE => ([], []),
     fn SOME (Syntax.Prefix delim) => ([delim], []),
     fn SOME (Syntax.Infix {assoc, delim, pri}) =>
       let
         val ass =
           (case assoc of
             Printer.No_Assoc => 0
           | Printer.Left_Assoc => 1
           | Printer.Right_Assoc => 2);
         open XML.Encode Term_XML.Encode;
       in ([], triple int string int (ass, delim, pri)) end];
 
 
 (* free variables: not declared in the context *)
 
 val is_free = not oo Name.is_declared;
 
 fun add_frees used =
   fold_aterms (fn Free (x, T) => is_free used x ? insert (op =) (x, T) | _ => I);
 
 fun add_tfrees used =
   (fold_types o fold_atyps) (fn TFree (a, S) => is_free used a ? insert (op =) (a, S) | _ => I);
 
 
 (* spec rules *)
 
 fun primrec_types ctxt const =
   Spec_Rules.retrieve ctxt (Const const)
   |> get_first
     (#rough_classification #>
       (fn Spec_Rules.Equational (Spec_Rules.Primrec types) => SOME (types, false)
         | Spec_Rules.Equational (Spec_Rules.Primcorec types) => SOME (types, true)
         | _ => NONE))
   |> the_default ([], false);
 
 
 (* locales *)
 
 fun locale_content thy loc =
   let
     val ctxt = Locale.init loc thy;
     val args =
       Locale.params_of thy loc
       |> map (fn ((x, T), _) => ((x, T), get_syntax_param ctxt loc x));
     val axioms =
       let
         val (asm, defs) = Locale.specification_of thy loc;
         val cprops = map (Thm.cterm_of ctxt) (the_list asm @ defs);
         val (intro1, intro2) = Locale.intros_of thy loc;
         val intros_tac = Method.try_intros_tac ctxt (the_list intro1 @ the_list intro2) [];
         val res =
           Goal.init (Conjunction.mk_conjunction_balanced cprops)
           |> (ALLGOALS Goal.conjunction_tac THEN intros_tac)
           |> try Seq.hd;
       in
         (case res of
           SOME goal => Thm.prems_of goal
         | NONE => raise Fail ("Cannot unfold locale " ^ quote loc))
       end;
     val typargs = rev (fold Term.add_tfrees (map (Free o #1) args @ axioms) []);
   in {typargs = typargs, args = args, axioms = axioms} end;
 
 fun get_locales thy =
   Locale.get_locales thy |> map_filter (fn loc =>
     if Experiment.is_experiment thy loc then NONE else SOME (loc, ()));
 
 fun get_dependencies prev_thys thy =
   Locale.dest_dependencies prev_thys thy |> map_filter (fn dep =>
     if Experiment.is_experiment thy (#source dep) orelse
       Experiment.is_experiment thy (#target dep) then NONE
     else
       let
         val (type_params, params) = Locale.parameters_of thy (#source dep);
         val typargs = fold (Term.add_tfreesT o #2 o #1) params type_params;
         val substT =
           typargs |> map_filter (fn v =>
             let
               val T = TFree v;
               val T' = Morphism.typ (#morphism dep) T;
             in if T = T' then NONE else SOME (v, T') end);
         val subst =
           params |> map_filter (fn (v, _) =>
             let
               val t = Free v;
               val t' = Morphism.term (#morphism dep) t;
             in if t aconv t' then NONE else SOME (v, t') end);
       in SOME (dep, (substT, subst)) end);
 
 
 (* spec rules *)
 
-fun spec_content (spec: Spec_Rules.spec) =
+fun spec_content {pos, name, rough_classification, terms = terms0, rules = rules0} =
   let
-    val {pos, name, rough_classification, terms = terms0, rules = rules0} = spec;
     val terms = map Logic.unvarify_global terms0;
     val rules = map (Logic.unvarify_global o Thm.plain_prop_of) rules0;
     val text = terms @ rules;
   in
    {props = Position.properties_of pos,
     name = name,
     rough_classification = rough_classification,
     typargs = rev (fold Term.add_tfrees text []),
     args = rev (fold Term.add_frees text []),
     terms = terms,
     rules = rules}
   end;
 
 
 (* general setup *)
 
 fun setup_presentation f =
   Theory.setup (Thy_Info.add_presentation (fn context => fn thy =>
     if Options.bool (#options context) "export_theory" then f context thy else ()));
 
 fun export_body thy name body =
   if XML.is_empty_body body then ()
   else Export.export thy (Path.binding0 (Path.make ["theory", name])) body;
 
 
 (* presentation *)
 
 val _ = setup_presentation (fn {adjust_pos, ...} => fn thy =>
   let
     val parents = Theory.parents_of thy;
     val rep_tsig = Type.rep_tsig (Sign.tsig_of thy);
 
     val thy_ctxt = Proof_Context.init_global thy;
 
 
     (* entities *)
 
     fun make_entity_markup name xname pos serial =
       let
         val props =
           Position.offset_properties_of (adjust_pos pos) @
           Position.id_properties_of pos @
           Markup.serial_properties serial;
       in (Markup.entityN, (Markup.nameN, name) :: (Markup.xnameN, xname) :: props) end;
 
     fun entity_markup space name =
       let
         val xname = Name_Space.extern_shortest thy_ctxt space name;
         val {serial, pos, ...} = Name_Space.the_entry space name;
       in make_entity_markup name xname pos serial end;
 
     fun export_entities export_name export get_space decls =
       let
         val parent_spaces = map get_space parents;
         val space = get_space thy;
       in
         (decls, []) |-> fold (fn (name, decl) =>
           if exists (fn space => Name_Space.declared space name) parent_spaces then I
           else
             (case export name decl of
               NONE => I
             | SOME body =>
                 cons (#serial (Name_Space.the_entry space name),
                   XML.Elem (entity_markup space name, body))))
         |> sort (int_ord o apply2 #1) |> map #2
         |> export_body thy export_name
       end;
 
 
     (* types *)
 
     val encode_type =
       let open XML.Encode Term_XML.Encode
       in triple encode_syntax (list string) (option typ) end;
 
     fun export_type c (Type.LogicalType n) =
           SOME (encode_type (get_syntax_type thy_ctxt c, Name.invent Name.context Name.aT n, NONE))
       | export_type c (Type.Abbreviation (args, U, false)) =
           SOME (encode_type (get_syntax_type thy_ctxt c, args, SOME U))
       | export_type _ _ = NONE;
 
     val _ =
       export_entities "types" export_type Sign.type_space
         (Name_Space.dest_table (#types rep_tsig));
 
 
     (* consts *)
 
     val consts = Sign.consts_of thy;
     val encode_term = Term_XML.Encode.term consts;
 
     val encode_const =
       let open XML.Encode Term_XML.Encode in
         pair encode_syntax
           (pair (list string)
             (pair typ (pair (option encode_term) (pair bool (pair (list string) bool)))))
       end;
 
     fun export_const c (T, abbrev) =
       let
         val syntax = get_syntax_const thy_ctxt c;
         val U = Logic.unvarifyT_global T;
         val U0 = Type.strip_sorts U;
         val recursion = primrec_types thy_ctxt (c, U);
         val abbrev' = abbrev
           |> Option.map (Proofterm.standard_vars_term Name.context #> map_types Type.strip_sorts);
         val args = map (#1 o dest_TFree) (Consts.typargs consts (c, U0));
         val propositional = Object_Logic.is_propositional thy_ctxt (Term.body_type U0);
       in encode_const (syntax, (args, (U0, (abbrev', (propositional, recursion))))) end;
 
     val _ =
       export_entities "consts" (SOME oo export_const) Sign.const_space
         (#constants (Consts.dest consts));
 
 
     (* axioms *)
 
     fun standard_prop used extra_shyps raw_prop raw_proof =
       let
         val (prop, proof) = Proofterm.standard_vars used (raw_prop, raw_proof);
         val args = rev (add_frees used prop []);
         val typargs = rev (add_tfrees used prop []);
         val used_typargs = fold (Name.declare o #1) typargs used;
         val sorts = Name.invent used_typargs Name.aT (length extra_shyps) ~~ extra_shyps;
       in ((sorts @ typargs, args, prop), proof) end;
 
     fun standard_prop_of thm =
       standard_prop Name.context (Thm.extra_shyps thm) (Thm.full_prop_of thm);
 
     val encode_prop =
       let open XML.Encode Term_XML.Encode
       in triple (list (pair string sort)) (list (pair string typ)) encode_term end;
 
     fun encode_axiom used prop =
       encode_prop (#1 (standard_prop used [] prop NONE));
 
     val _ =
       export_entities "axioms" (K (SOME o encode_axiom Name.context))
         Theory.axiom_space (Theory.all_axioms_of thy);
 
 
     (* theorems and proof terms *)
 
     val clean_thm = Thm.check_hyps (Context.Theory thy) #> Thm.strip_shyps;
     val prep_thm = clean_thm #> Thm.unconstrainT;
 
     val lookup_thm_id = Global_Theory.lookup_thm_id thy;
 
     fun expand_name thm_id (header: Proofterm.thm_header) =
       if #serial header = #serial thm_id then ""
       else
         (case lookup_thm_id (Proofterm.thm_header_id header) of
           NONE => ""
         | SOME thm_name => Thm_Name.print thm_name);
 
     fun entity_markup_thm (serial, (name, i)) =
       let
         val space = Facts.space_of (Global_Theory.facts_of thy);
         val xname = Name_Space.extern_shortest thy_ctxt space name;
         val {pos, ...} = Name_Space.the_entry space name;
       in make_entity_markup (Thm_Name.print (name, i)) (Thm_Name.print (xname, i)) pos serial end;
 
     fun encode_thm thm_id raw_thm =
       let
         val deps = map (Thm_Name.print o #2) (Thm_Deps.thm_deps thy [raw_thm]);
         val thm = prep_thm raw_thm;
 
         val proof0 =
           if Proofterm.export_standard_enabled () then
             Proof_Syntax.standard_proof_of
               {full = true, expand_name = SOME o expand_name thm_id} thm
           else if Proofterm.export_enabled () then Thm.reconstruct_proof_of thm
           else MinProof;
         val (prop, SOME proof) = standard_prop_of thm (SOME proof0);
         val _ = Thm.expose_proofs thy [thm];
       in
         (prop, deps, proof) |>
           let
             open XML.Encode Term_XML.Encode;
             val encode_proof = Proofterm.encode_standard_proof consts;
           in triple encode_prop (list string) encode_proof end
       end;
 
     fun export_thm (thm_id, thm_name) =
       let
         val markup = entity_markup_thm (#serial thm_id, thm_name);
         val thm = Global_Theory.get_thm_name thy (thm_name, Position.none);
       in XML.Elem (markup, encode_thm thm_id thm) end;
 
     val _ = export_body thy "thms" (map export_thm (Global_Theory.dest_thm_names thy));
 
 
     (* type classes *)
 
     val encode_class =
       let open XML.Encode Term_XML.Encode
       in pair (list (pair string typ)) (list (encode_axiom Name.context)) end;
 
     fun export_class name =
       (case try (Axclass.get_info thy) name of
         NONE => ([], [])
       | SOME {params, axioms, ...} => (params, map (Thm.plain_prop_of o clean_thm) axioms))
       |> encode_class |> SOME;
 
     val _ =
       export_entities "classes" (fn name => fn () => export_class name)
         Sign.class_space (map (rpair ()) (Graph.keys (Sorts.classes_of (#2 (#classes rep_tsig)))));
 
 
     (* sort algebra *)
 
     local
       val prop = encode_axiom Name.context o Logic.varify_global;
 
       val encode_classrel =
         let open XML.Encode
         in list (pair prop (pair string string)) end;
 
       val encode_arities =
         let open XML.Encode Term_XML.Encode
         in list (pair prop (triple string (list sort) string)) end;
     in
       val export_classrel =
         maps (fn (c, cs) => map (pair c) cs) #> map (`Logic.mk_classrel) #> encode_classrel;
 
       val export_arities = map (`Logic.mk_arity) #> encode_arities;
 
       val {classrel, arities} =
         Sorts.dest_algebra (map (#2 o #classes o Type.rep_tsig o Sign.tsig_of) parents)
           (#2 (#classes rep_tsig));
     end;
 
     val _ = if null classrel then () else export_body thy "classrel" (export_classrel classrel);
     val _ = if null arities then () else export_body thy "arities" (export_arities arities);
 
 
     (* locales *)
 
     fun encode_locale used =
       let open XML.Encode Term_XML.Encode in
         triple (list (pair string sort)) (list (pair (pair string typ) encode_syntax))
           (list (encode_axiom used))
       end;
 
     fun export_locale loc =
       let
         val {typargs, args, axioms} = locale_content thy loc;
         val used = fold Name.declare (map #1 typargs @ map (#1 o #1) args) Name.context;
       in encode_locale used (typargs, args, axioms) end
       handle ERROR msg =>
         cat_error msg ("The error(s) above occurred in locale " ^
           quote (Locale.markup_name thy_ctxt loc));
 
     val _ =
       export_entities "locales" (fn loc => fn () => SOME (export_locale loc))
         Locale.locale_space (get_locales thy);
 
 
     (* locale dependencies *)
 
     fun encode_locale_dependency (dep: Locale.locale_dependency, subst) =
       (#source dep, (#target dep, (#prefix dep, subst))) |>
         let
           open XML.Encode Term_XML.Encode;
           val encode_subst =
             pair (list (pair (pair string sort) typ)) (list (pair (pair string typ) (term consts)));
         in pair string (pair string (pair (list (pair string bool)) encode_subst)) end;
 
     val _ =
       get_dependencies parents thy
       |> map_index (fn (i, dep) =>
         let
           val xname = string_of_int (i + 1);
           val name = Long_Name.implode [Context.theory_name thy, xname];
           val markup = make_entity_markup name xname (#pos (#1 dep)) (#serial (#1 dep));
           val body = encode_locale_dependency dep;
         in XML.Elem (markup, body) end)
       |> export_body thy "locale_dependencies";
 
 
     (* constdefs *)
 
     val constdefs =
       Defs.dest_constdefs (map Theory.defs_of (Theory.parents_of thy)) (Theory.defs_of thy)
       |> sort_by #1;
 
     val encode_constdefs =
       let open XML.Encode
       in list (pair string string) end;
 
     val _ =
       if null constdefs then () else export_body thy "constdefs" (encode_constdefs constdefs);
 
 
     (* spec rules *)
 
     val encode_specs =
       let open XML.Encode Term_XML.Encode in
         list (fn {props, name, rough_classification, typargs, args, terms, rules} =>
           pair properties (pair string (pair Spec_Rules.encode_rough_classification
             (pair (list (pair string sort)) (pair (list (pair string typ))
               (pair (list encode_term) (list encode_term))))))
               (props, (name, (rough_classification, (typargs, (args, (terms, rules)))))))
       end;
 
     val _ =
       (case Spec_Rules.dest_theory thy of
         [] => ()
       | spec_rules => export_body thy "spec_rules" (encode_specs (map spec_content spec_rules)));
 
 
     (* parents *)
 
     val _ =
       Export.export thy \<^path_binding>\<open>theory/parents\<close>
         (XML.Encode.string (cat_lines (map Context.theory_long_name parents)));
 
   in () end);
 
 end;