premise: Thomas has only visited Canada, Stephen has only visited Bhutan, Arthur has only visited Trinidad & Tobago, Barry has only visited Rwanda, Edward has only visited Mozambique, Harold has only visited Nauru, Cory has only visited Bolivia, Clifford has only visited Honduras, Jeff has only visited Laos, Ian has only visited Lebanon, Aaron has only visited Papua New Guinea, Tom has only visited Madagascar
hypothesis: Tom didn't visit Guinea