A boreal forest can be closed.Logical formLearned from5 sentences. (Payload bay doors) can be closed.Logical formLearned from5 sentences. A closed surface can be simple.Logical formLearned from5 sentences. A source can be closed.Logical formLearned from5 sentences. Counterparts can be closed.Logical formLearned from5 sentences. A current can be closed.Logical formLearned from5 sentences. A n-manifold can be closed.Logical formLearned from5 sentences. Pieces can be closed.Logical formLearned from5 sentences. Dots can be closed.Logical formLearned from5 sentences. Streams can be closed.Logical formLearned from5 sentences. (Storage rooms) can be closed.Logical formLearned from5 sentences. A sense can be closed.Logical formLearned from5 sentences. A party can be closed.Logical formLearned from5 sentences. A (development model) can be closed.Logical formLearned from5 sentences. Variances may be expressed in closed form.Logical formLearned from5 sentences.