Stairs may undergo maintenance.Logical formLearned from3 sentences. Stairs may connect a platform.Logical formLearned from3 sentences. A stair can be crooked.Logical formLearned from3 sentences. Stairs may lead to a front porch.Logical formLearned from3 sentences. A flight can be constituted-of-or-filled-with (steel stairs).Logical formLearned from3 sentences. Stairs can be to a platform.Logical formLearned from3 sentences. A side may have some (street stairs).Logical formLearned from3 sentences. Stairs can be closed.Logical formLearned from3 sentences. Room can be at a top of stairs.Logical formLearned from3 sentences. Some stairs can be to a platform.Logical formLearned from3 sentences. A head may hit stairs.Logical formLearned from3 sentences. Platforms may be accessed by stairs.Logical formLearned from3 sentences. A base may pertain-to a stair.Logical formLearned from3 sentences. Entry to caves can be through narrow stairs.Logical formLearned from3 sentences. Some denizens may travel on a stair.Logical formLearned from3 sentences.