diff --git a/funcons-values.cabal b/funcons-values.cabal
--- a/funcons-values.cabal
+++ b/funcons-values.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                funcons-values
-version:             0.1.0.0
+version:             0.1.0.2
 synopsis:            Library providing values and operations on values.
 -- description:
 homepage:            http://plancomps.org
diff --git a/src/Funcons/Operations/Strings.hs b/src/Funcons/Operations/Strings.hs
--- a/src/Funcons/Operations/Strings.hs
+++ b/src/Funcons/Operations/Strings.hs
@@ -31,6 +31,10 @@
 stepTo_String (Float f)         = mk_string  (show f)
 stepTo_String (IEEE_Float_32 f) = mk_string  (show f)
 stepTo_String (IEEE_Float_64 d) = mk_string  (show d)
+stepTo_String (ADTVal "true" []) = mk_string "true"
+stepTo_String (ADTVal "false"[]) = mk_string "false"
+stepTo_String (ADTVal "none"[]) = mk_string "none"
+stepTo_String v | isString_ v   = mk_string (unString v)
 stepTo_String v                 = DomErr ("to-string undefined on this type")
 
 mk_string :: HasValues t => String -> Result t