Letters may undergo a sampling.Logical formLearned from26 sentences. A female can be letters.Logical formLearned from26 sentences. An old man may write a letter to a son.Logical formLearned from26 sentences. A (resignation letter) can be formal.Logical formLearned from26 sentences. Persons may show letters to supporters.Logical formLearned from26 sentences. A letter can be to an (email address).Logical formLearned from26 sentences. Letters may be posted.Logical formLearned from26 sentences. Letters may undergo an examination.Logical formLearned from26 sentences. A US-president may write in a letter.Logical formLearned from26 sentences. A letters may undergo a collection.Logical formLearned from26 sentences. A letter can be necessary.Logical formLearned from26 sentences. Some letters can be in a language.Logical formLearned from26 sentences. Letters may contain anthrax.Logical formLearned from26 sentences. A letter can be from an author.Logical formLearned from26 sentences. A letter may promise that something-is-the-case.Logical formLearned from26 sentences.