anchor.diff:  
   -record(regexp, {source, compiled}).
   
  +%% Types '$1','$2' and '_' are needed for match specs to ets:select
   -record(app,
           { %% Static info
  -          name             :: app_name(),
  -          is_escript       :: boolean() | {inlined, escript_app_name()},
  -          use_selected_vsn :: vsn | dir | undefined,
  -          active_dir       :: dir(),
  -          sorted_dirs      :: [dir()],
  -          vsn              :: app_vsn(),
  -          label            :: app_label(),
  -          info             :: #app_info{} | undefined,
  -          mods             :: [#mod{}],
  +          name             :: '_' | app_name(),
  +          is_escript       :: '_' | boolean() | {inlined, escript_app_name()},
  +          use_selected_vsn :: '_' | vsn | dir | undefined,
  +          active_dir       :: '_' | dir(),
  +          sorted_dirs      :: '_' | [dir()],
  +          vsn              :: '_' | app_vsn(),
  +          label            :: '_' | app_label(),
  +          info             :: '_' | #app_info{} | undefined,
  +          mods             :: '_' | [#mod{}],
   
             %% Static source cond
  -          mod_cond  :: mod_cond()  | undefined,
  -          incl_cond :: incl_cond() | undefined,
  +          mod_cond  :: '_' | mod_cond()  | undefined,
  +          incl_cond :: '_' | incl_cond() | undefined,
   
             %% Static target cond
  -          debug_info            :: debug_info() | undefined,
  -          app_file              :: app_file() | undefined,
  -          app_type              :: app_type() | undefined,
  -          incl_app_filters      :: [#regexp{}],
  -          excl_app_filters      :: [#regexp{}],
  -          incl_archive_filters  :: [#regexp{}],
  -          excl_archive_filters  :: [#regexp{}],
  -          archive_opts          :: [archive_opt()],
  +          debug_info            :: '_' | debug_info() | undefined,
  +          app_file              :: '_' | app_file() | undefined,
  +          app_type              :: '_' | app_type() | undefined,
  +          incl_app_filters      :: '_' | [#regexp{}],
  +          excl_app_filters      :: '_' | [#regexp{}],
  +          incl_archive_filters  :: '_' | [#regexp{}],
  +          excl_archive_filters  :: '_' | [#regexp{}],
  +          archive_opts          :: '_' | [archive_opt()],
   
             %% Dynamic
  -          status          :: status(),
  -          uses_mods       :: [mod_name()],
  -          used_by_mods    :: [mod_name()],
  -          uses_apps       :: [app_name()],
  -          used_by_apps    :: [app_name()],
  -          is_pre_included :: boolean() | undefined,
  -          is_included     :: boolean() | undefined,
  -          rels            :: [rel_name()]
  +          status          :: '_' | status(),
  +          uses_mods       :: '_' | [mod_name()],
  +          used_by_mods    :: '_' | [mod_name()],
  +          uses_apps       :: '_' | [app_name()],
  +          used_by_apps    :: '_' | [app_name()],
  +          is_pre_included :: '_' | '$2' | boolean() | undefined,
  +          is_included     :: '_' | '$1' | boolean() | undefined,
  +          rels            :: '_' | [rel_name()]
   	}).
   
   -record(rel_app,
  
positive.code:           escripts  :: [file()],
            mod_cond  :: mod_cond(),
            incl_cond :: incl_cond(),
            apps      :: [#app{}],
  
            %% Target cond
            boot_rel 	       :: boot_rel(),
  
negative.code:           trap_exit 	  :: boolean()
  	}).
  
  %% Types '$1','$2' and '_' are needed for match specs to ets:select
  -record(mod,
          { %% Static
            name        :: '$1' | mod_name(),
            app_name    :: '_'  | app_name(),
            incl_cond   :: '_'  | incl_cond() | undefined,
            debug_info  :: '_'  | debug_info() | undefined,
            is_app_mod  :: '_'  | boolean(),
            is_ebin_mod :: '_'  | boolean(),
            uses_mods   :: '$2' | [mod_name()],
            exists      :: '_'  | boolean(),
            %% Dynamic
            status          :: '_' | status(),
            used_by_mods    :: '_' | [mod_name()],
            is_pre_included :: '_' | boolean() | undefined,
            is_included     :: '_' | boolean() | undefined
  	}).
  
  -record(app_info,
  