Error found:
in module Main
at tests/purs/failing/TypeSynonyms9.purs:7:19 - 7:29 (line 7, column 19 - line 7, column 29)

  Type synonym Data.NaturalTransformation.NaturalTransformation is partially applied.
  Type synonyms must be applied to all of their type arguments.

while checking that type NaturalTransformation Array
  has kind (Type -> Type) -> Type -> Type
while inferring the kind of A (NaturalTransformation Array)
in type constructor B

See https://github.com/purescript/documentation/blob/master/errors/PartiallyAppliedSynonym.md for more information,
or to contribute content related to this error.