src/Pure/Isar/keyword.ML

   val no_command_keywords: keywords -> keywords
   val empty_keywords: keywords
   val merge_keywords: keywords * keywords -> keywords
   val add_keywords: ((string * Position.T) * spec) list -> keywords -> keywords
   val add_minor_keywords: string list -> keywords -> keywords
+  val add_major_keywords: string list -> keywords -> keywords
   val is_keyword: keywords -> string -> bool
   val is_command: keywords -> string -> bool
   val is_literal: keywords -> string -> bool
   val dest_commands: keywords -> string list
   val command_markup: keywords -> string -> Markup.T option

       in (minor, major', commands') end));
 
 val add_minor_keywords =
   add_keywords o map (fn name => ((name, Position.none), no_spec));
 
+val add_major_keywords =
+  add_keywords o map (fn name => ((name, Position.none), (diag, [])));
+
 
 (* keyword status *)
 
 fun is_keyword keywords s = Scan.is_literal (minor_keywords keywords) (Symbol.explode s);
 fun is_command (Keywords {commands, ...}) = Symtab.defined commands;