A male may back_down stairs.Logical formLearned from3 sentences. (Brass nosings) may pertain-to stairs.Logical formLearned from3 sentences. Great numbers of persons may pass over stairs.Logical formLearned from3 sentences. Persons may climb stairs.Logical formLearned from3 sentences. A (stair climb race) can be annual.Logical formLearned from3 sentences. Stairs can be to an entrance.Logical formLearned from3 sentences. A male may step to a stair.Logical formLearned from3 sentences. A lurker can be on stairs.Logical formLearned from3 sentences. A spitting can be on stairs.Logical formLearned from3 sentences. A (stair hall) can be grand.Logical formLearned from3 sentences. A person may exit stairs.Logical formLearned from3 sentences. A building may lead to stairs.Logical formLearned from3 sentences. A male may come upon stairs.Logical formLearned from3 sentences. A sound may come from stairs.Logical formLearned from3 sentences. An officer may climb stairs.Logical formLearned from3 sentences.