∀ {filename : Option String} {osCode : UInt32} {details : String} {filename_1 : Option String} {osCode_1 : UInt32}
  {details_1 : String},
  IO.Error.inappropriateType filename osCode details = IO.Error.inappropriateType filename_1 osCode_1 details_1 →
    filename = filename_1 ∧ osCode = osCode_1 ∧ details = details_1