Added another bug.

src/TypeChecker/Bugs.md

@@ -27,3 +27,39 @@ Program below should not type check
 main : a -> b ;
 main x = x;
 ```
+
+## Bugged error message
+```hs
+data Maybe () where {
+    Nothing : Maybe
+    Just : Int -> Maybe
+    };
+
+fmap : (Int -> Int) -> Maybe -> Maybe ;
+fmap f ma = case ma of {
+    Nothing => Nothing ;
+    Just a => Just (f a) ;
+};
+
+pure : Int -> Maybe ;
+pure x = Just x ;
+
+ap mf ma = case mf of {
+    Just f => case ma of {
+        Nothing => Nothing;
+        Just a => Just (f a);
+    };
+    Nothing => Nothing;
+};
+    
+return = pure;
+
+bind ma f = case ma of {
+    Nothing => Nothing ;
+    Just a => f a ;
+};
+```
+```
+TYPECHECKER ERROR
+Inferred type '("c" -> "Int") -> "Maybe" -> "Maybe" does not match specified type '("Int" -> "Int") -> "Maybe" -> "Maybe"'
+```