tutorial semantics example works except one rul

examples-3.0/tutorial/semantics/Top.hs

@@ -0,0 +1,23 @@
+module Main where
+
+import GSyntax
+import SemBase
+import Logic
+import GF.GFCC.API
+
+main :: IO ()
+main = do
+  gr <- file2grammar "base.gfcc"
+  loop gr
+
+loop :: MultiGrammar -> IO ()
+loop gr = do
+  s <- getLine
+  let t:_ = parse gr "BaseEng" "S" s
+  putStrLn $ showTree t
+  let p = iS $ fg t
+  putStrLn $ show p
+  let v = valProp exModel [] p
+  putStrLn $ show v
+  loop gr
+