gadt-escape1.hs:19:58:
    Couldn't match type ‛t’ with ‛ExpGADT Int’
      ‛t’ is untouchable
        inside the constraints (t1 ~ Int)
        bound by a pattern with constructor
                   ExpInt :: Int -> ExpGADT Int,
                 in a case alternative
        at gadt-escape1.hs:19:43-50
      ‛t’ is a rigid type variable bound by
          the inferred type of weird1 :: t at gadt-escape1.hs:19:1
    Expected type: t
      Actual type: ExpGADT t1
    Relevant bindings include
      weird1 :: t (bound at gadt-escape1.hs:19:1)
    In the expression: a
    In a case alternative: Hidden (ExpInt _) a -> a