Letters may stop.Logical formLearned from96 sentences. Stacks can be constituted-of-or-filled-with letters.Logical formLearned from96 sentences. Letters can be repeated.Logical formLearned from96 sentences. A letter may contain anthrax.Logical formLearned from96 sentences. A letter may contain a powder.Logical formLearned from96 sentences. An open letter can be to a government.Logical formLearned from96 sentences. A letter may be signed by a male.Logical formLearned from95 sentences. A letter can be to a mayor.Logical formLearned from95 sentences. Letters can be electronic.Logical formLearned from95 sentences. A letter may undergo writing.Logical formLearned from95 sentences. A letter can be for a male.Logical formLearned from95 sentences. A reason can be for a letter.Logical formLearned from95 sentences. Letters may undergo a selection.Logical formLearned from95 sentences. A letter may pertain-to an editor.Logical formLearned from95 sentences. A packet can be constituted-of-or-filled-with letters.Logical formLearned from95 sentences.