diff --git a/src/GF/Command/Commands.hs b/src/GF/Command/Commands.hs
index 282bd3066..584535279 100644
--- a/src/GF/Command/Commands.hs
+++ b/src/GF/Command/Commands.hs
@@ -615,12 +615,15 @@ allCommands cod env@(pgf, mos) = Map.fromList [
      }),
   ("ai", emptyCommandInfo {
      longname = "abstract_info",
-     syntax = "ai IDENTIFIER",
-     synopsis = "provides an information about a function or a category from the abstract syntax",
+     syntax = "ai IDENTIFIER  or  ai EXPR",
+     synopsis = "Provides an information about a function, an expression or a category from the abstract syntax",
      explanation = unlines [
-       "The command has one argument which is either function or a category defined in",
-       "the abstract syntax of the current grammar. If the argument is a function then",
-       "its type is printed out. If it is a category then the category definition is printed"
+       "The command has one argument which is either function, expression or",
+       "a category defined in the abstract syntax of the current grammar. ",
+       "If the argument is a function then ?its type is printed out.",
+       "If it is a category then the category definition is printed.",
+       "If a whole expression is given it prints the expression with refined",
+       "metavariables and the type of the expression."
        ],
      exec = \opts arg -> do
        case arg of
diff --git a/src/PGF/Expr.hs b/src/PGF/Expr.hs
index 97eb49f00..48d286ea1 100644
--- a/src/PGF/Expr.hs
+++ b/src/PGF/Expr.hs
@@ -186,10 +186,11 @@ ppExpr d scope (EFun f)     = ppCId f
 ppExpr d scope (EVar i)     = ppCId (scope !! i)
 ppExpr d scope (ETyped e ty)= ppParens (d > 0) (ppExpr 0 scope e PP.<+> PP.colon PP.<+> ppType 0 scope ty)
 
+ppPatt :: Int -> [CId] -> Patt -> ([CId],PP.Doc)
 ppPatt d scope (PApp f ps) = let (scope',ds) = mapAccumL (ppPatt 2) scope ps
                              in (scope',ppParens (not (List.null ps) && d > 1) (ppCId f PP.<+> PP.hsep ds))
 ppPatt d scope (PLit l)    = (scope,ppLit l)
-ppPatt d scope (PVar f)    = (scope,ppCId f)
+ppPatt d scope (PVar f)    = (f:scope,ppCId f)
 ppPatt d scope PWild       = (scope,PP.char '_')
 
 ppLit (LStr s) = PP.text (show s)