A male may tumble_down a flight of stairs.Logical formLearned from7 sentences. A male may climb some flights of stairs.Logical formLearned from7 sentences. A male may climb stairs to an office.Logical formLearned from7 sentences. Stairs may lead to a (basement office).Logical formLearned from7 sentences. A male may sprint_up stairs.Logical formLearned from7 sentences. Persons can be on stairs.Logical formLearned from7 sentences. A male may fall on stairs.Logical formLearned from7 sentences. A male may be tripped on some stairs.Logical formLearned from7 sentences. Stairs can be difficult.Logical formLearned from6 sentences. A close may pertain-to stair.Logical formLearned from6 sentences. A need can be for stairs.Logical formLearned from6 sentences. Stairs can be to a street.Logical formLearned from6 sentences. A male may go for stairs.Logical formLearned from6 sentences. Stairs can be with a heavy load.Logical formLearned from6 sentences. A half-flight can be constituted-of-or-filled-with stairs.Logical formLearned from6 sentences.