premise: Micheal has only visited Oman, Edwin has only visited United States, Allan has only visited São Tomé & Prícipe, Juan has only visited Vatican City, Jessie has only visited Marshall Islands, Marc has only visited Seychelles, Greg has only visited Sierra Leone, James has only visited Iran, Eric has only visited Timor-Leste, Joel has only visited Luxembourg, Herman has only visited Mongolia
hypothesis: Bradley didn't visit Sierra Leone