diff --git a/prelude/Predef.gf b/prelude/Predef.gf
index 961e99eb3..0b93b7f57 100644
--- a/prelude/Predef.gf
+++ b/prelude/Predef.gf
@@ -22,7 +22,9 @@ resource Predef = {
   oper occur  : Tok -> Tok -> PBool    = variants {} ; -- test if occurs as substring
   oper show   : (P : Type) -> P -> Tok = variants {} ; -- convert param to string
   oper read   : (P : Type) -> Tok -> P = variants {} ; -- convert string to param
-  oper toStr  : (P : Type) -> P -> Str = variants {} ; -- find the "first" string
+  oper toStr  : (L : Type) -> L -> Str = variants {} ; -- find the "first" string
+  oper mapStr : (L : Type) -> (Str -> Str) -> L -> L = variants {} ; 
+               -- map all strings in a data structure
 
   } ;
 
diff --git a/resource/english/RulesEng.gf b/resource/english/RulesEng.gf
index fe934e7b9..27ecc4881 100644
--- a/resource/english/RulesEng.gf
+++ b/resource/english/RulesEng.gf
@@ -29,7 +29,7 @@ flags
   optimize=all ;
 
 lin 
-  UseN = noun2CommNounPhrase ;
+  UseN  = noun2CommNounPhrase ;
   UsePN = nameNounPhrase ;
 
   SymbPN i = {s = table {Nom => i.s ; Gen => i.s ++ "'s"} ; g = Neutr} ; ---