premise: Frederick has only visited Lebanon, Tyler has only visited Romania, Johnnie has only visited Niger, Vernon has only visited San Mmarino, Carl has only visited Kuwait, Glenn has only visited Belarus, William has only visited Vanuatu, Randy has only visited Palau, Manuel has only visited Montenegro, Philip has only visited Eswatini, Jerome has only visited Guinea-Bissau, Jeremy has only visited Vietnam
hypothesis: Eric didn't visit Niger