T7453.hs:10:30: error:
    • Couldn't match expected type ‘t’ with actual type ‘p’
      ‘t’ is a rigid type variable bound by
        the type signature for:
          z :: forall t. Id t
        at T7453.hs:8:11-19
      ‘p’ is a rigid type variable bound by
        the inferred type of cast1 :: p -> a
        at T7453.hs:(7,1)-(10,30)
    • In the first argument of ‘Id’, namely ‘v’
      In the expression: Id v
      In an equation for ‘aux’: aux = Id v
    • Relevant bindings include
        aux :: Id t (bound at T7453.hs:10:21)
        z :: Id t (bound at T7453.hs:9:11)
        v :: p (bound at T7453.hs:7:7)
        cast1 :: p -> a (bound at T7453.hs:7:1)

T7453.hs:16:33: error:
    • Couldn't match expected type ‘t1’ with actual type ‘p’
      ‘t1’ is a rigid type variable bound by
        the type signature for:
          z :: forall t1. () -> t1
        at T7453.hs:14:11-22
      ‘p’ is a rigid type variable bound by
        the inferred type of cast2 :: p -> t
        at T7453.hs:(13,1)-(16,33)
    • In the first argument of ‘const’, namely ‘v’
      In the expression: const v
      In an equation for ‘aux’: aux = const v
    • Relevant bindings include
        aux :: b -> t1 (bound at T7453.hs:16:21)
        z :: () -> t1 (bound at T7453.hs:15:11)
        v :: p (bound at T7453.hs:13:7)
        cast2 :: p -> t (bound at T7453.hs:13:1)

T7453.hs:21:15: error:
    • Couldn't match expected type ‘t1’ with actual type ‘p’
      ‘t1’ is a rigid type variable bound by
        the type signature for:
          z :: forall t1. t1
        at T7453.hs:20:11-16
      ‘p’ is a rigid type variable bound by
        the inferred type of cast3 :: p -> t
        at T7453.hs:(19,1)-(22,33)
    • In the expression: v
      In an equation for ‘z’:
          z = v
            where
                aux = const v
      In an equation for ‘cast3’:
          cast3 v
            = z
            where
                z :: t
                z = v
                  where
                      aux = const v
    • Relevant bindings include
        aux :: forall b. b -> p (bound at T7453.hs:22:21)
        z :: t1 (bound at T7453.hs:21:11)
        v :: p (bound at T7453.hs:19:7)
        cast3 :: p -> t (bound at T7453.hs:19:1)