now the datatype Tree is only internal. All API functions are working with Expr directly. Commands gt, gr, p and rf filter out the output via the typechecker

src/PGF/Parsing/FCFG/Utilities.hs

@@ -20,6 +20,7 @@ import Data.List (groupBy)
 
 import PGF.CId
 import PGF.Data
+import PGF.Tree
 import GF.Data.Assoc
 import GF.Data.Utilities (sameLength, foldMerge, splitBy)