Initial ternary representation options

Both parsing and conversion from T to ternary representation supported

src/Research.hs

@@ -88,6 +88,12 @@ toList (Fork x rest) = case toList rest of
   Left err -> Left err
 toList _ = Left "Invalid Tree Calculus list"
 
+-- Outputs
+toTernaryString :: T -> String
+toTernaryString Leaf = "0"
+toTernaryString (Stem t) = "1" ++ toTernaryString t
+toTernaryString (Fork t1 t2) = "2" ++ toTernaryString t1 ++ toTernaryString t2
+
 -- Utility
 type Env = Map.Map String T