A certificate may pertain-to an (air operator).Logical formLearned from21 sentences. An operator can be owned.Logical formLearned from21 sentences. A manual may pertain-to an operator.Logical formLearned from21 sentences. A (service operator) may pertain-to a country.Logical formLearned from21 sentences. (Tour operators) may pertain-to a country.Logical formLearned from21 sentences. A (tour operator) may collapse under pressure.Logical formLearned from21 sentences. Operators may pertain-to a continent.Logical formLearned from21 sentences. A (cell phone operator) can be in a country.Logical formLearned from21 sentences. A bunch can be constituted-of-or-filled-with operators.Logical formLearned from21 sentences. An operator may manage a grid.Logical formLearned from21 sentences. An operator may pertain-to a car.Logical formLearned from21 sentences. A (mobile phone operator) may pertain-to a country.Logical formLearned from21 sentences. Operators may undergo a selection.Logical formLearned from21 sentences. A (mine operator) can be underground.Logical formLearned from21 sentences. Operators may hold jobs.Logical formLearned from21 sentences.