Coal may undergo a search.Logical formLearned from15 sentences. (Coal mines) can be in a region.Logical formLearned from15 sentences. (Coal deposits) can be known.Logical formLearned from15 sentences. (Coal mining) can be in a region.Logical formLearned from15 sentences. Some tons of coal may be produced.Logical formLearned from15 sentences. A (coal consumption) can be high.Logical formLearned from15 sentences. A heap can be constituted-of-or-filled-with coals.Logical formLearned from15 sentences. Coal may rise.Logical formLearned from15 sentences. Canaries can be in (coal mines).Logical formLearned from15 sentences. A coal can be constituted-of-or-filled-with fire.Logical formLearned from15 sentences. Areas can be constituted-of-or-filled-with underground (coal mines).Logical formLearned from15 sentences. A coal can be processed.Logical formLearned from15 sentences. Equipment may be used in underground (coal mines).Logical formLearned from15 sentences. (Coal resources) may undergo a development.Logical formLearned from15 sentences. A country may burn coal.Logical formLearned from15 sentences.