Persons may sit on stairs.Logical formLearned from8 sentences. A female may hear footsteps on stairs.Logical formLearned from8 sentences. Access can be by stairs.Logical formLearned from8 sentences. Stairs can be reversed.Logical formLearned from8 sentences. A male may walk on stairs.Logical formLearned from8 sentences. A male may go_down stairs.Logical formLearned from8 sentences. Stairs may lead to stands.Logical formLearned from8 sentences. Stairs may be stained with blood.Logical formLearned from8 sentences. Stairs may pertain-to a dais.Logical formLearned from8 sentences. Stairs can be safe.Logical formLearned from8 sentences. Stairs can be icy.Logical formLearned from8 sentences. Stairs may pertain-to an aircraft.Logical formLearned from8 sentences. Persons may run to stairs.Logical formLearned from8 sentences. An entrance can be to stairs.Logical formLearned from7 sentences. A female may run_up stairs.Logical formLearned from7 sentences.