gadt7.hs:16:38: error: [GHC-25897]
    • Could not deduce ‘p1 ~ p2’
      from the context: a ~ Int
        bound by a pattern with constructor: K :: T Int,
                 in a case alternative
        at gadt7.hs:16:33
      ‘p1’ is a rigid type variable bound by
        the inferred type of i1b :: T a -> p1 -> p2
        at gadt7.hs:16:1-44
      ‘p2’ is a rigid type variable bound by
        the inferred type of i1b :: T a -> p1 -> p2
        at gadt7.hs:16:1-44
    • In the expression: y1
      In a case alternative: K -> y1
      In the expression: case t1 of K -> y1
    • Relevant bindings include
        y1 :: p1 (bound at gadt7.hs:16:16)
        y :: p1 (bound at gadt7.hs:16:7)
        i1b :: T a -> p1 -> p2 (bound at gadt7.hs:16:1)
    Suggested fix: Consider giving ‘i1b’ a type signature