A stair can be broken.Logical formLearned from12 sentences. A male may climb stairs to a second floor.Logical formLearned from12 sentences. Stairs can be difficult.Logical formLearned from12 sentences. (Stair lifts) can be curved.Logical formLearned from12 sentences. A male may get to a top of stairs.Logical formLearned from12 sentences. A person may get_down stairs.Logical formLearned from12 sentences. Stairs can be steep.Logical formLearned from12 sentences. A female can be at a top of stairs.Logical formLearned from12 sentences. A male may get_up stairs.Logical formLearned from12 sentences. A length may pertain-to stairs.Logical formLearned from12 sentences. A set can be constituted-of-or-filled-with (marble stairs).Logical formLearned from12 sentences. Persons may climb_up stairs.Logical formLearned from12 sentences. Stairs can be at a house.Logical formLearned from12 sentences. A person may fly_down stairs.Logical formLearned from12 sentences. A person may skip_down stairs.Logical formLearned from12 sentences.