A sign may tout benefits of using stairs.Logical formLearned from2 sentences. Signs may promote health of (stair use).Logical formLearned from2 sentences. Stairs may undergo an installation.Logical formLearned from2 sentences. A section can be constituted-of-or-filled-with stairs.Logical formLearned from2 sentences. A stair may pertain-to a hall.Logical formLearned from2 sentences. Feet may sound on stairs.Logical formLearned from2 sentences. (Stair openings) can be at a back of shops.Logical formLearned from2 sentences. Effects may pertain-to (stair openings).Logical formLearned from2 sentences. (Stair openings) can be in shops.Logical formLearned from2 sentences. A lack of (stair openings) may contribute to a seismic performance.Logical formLearned from2 sentences. A (stair opening) may sever a connection.Logical formLearned from2 sentences. A (stair opening) can be at a back of a shop.Logical formLearned from2 sentences. Significance may pertain-to (stair openings).Logical formLearned from2 sentences. A (stair opening) may prevent a connection.Logical formLearned from2 sentences. Figure may show a stair.Logical formLearned from2 sentences.