premise: Gordon has only visited Cuba, Clifford has only visited Colombia, Neil has only visited Dominica, James has only visited Madagascar, Tyler has only visited Honduras, Edgar has only visited Argentina, Kelly has only visited Mauritania, Clayton has only visited Mozambique, Mario has only visited Iraq, Marshall has only visited Guatemala, Joel has only visited Monaco, Carlos has only visited Djibouti
hypothesis: Gordon didn't visit São Tomé & Prícipe