Stairs can be empty.Logical formLearned from8 sentences. A male may run to stairs.Logical formLearned from8 sentences. Stairs can be to a kitchen.Logical formLearned from8 sentences. A male may trudge_down stairs.Logical formLearned from8 sentences. Stairs can be a problem.Logical formLearned from8 sentences. Stairs may undergo an addition.Logical formLearned from8 sentences. A male may sit_down on stairs.Logical formLearned from8 sentences. Stairs can be a part of a building.Logical formLearned from8 sentences. Persons may get on stairs.Logical formLearned from8 sentences. A female may run stairs.Logical formLearned from8 sentences. Someone can be on stairs.Logical formLearned from8 sentences. (Trainer & author) can be constituted-of-or-filled-with (stair exercises).Logical formLearned from8 sentences. Stairs can be tall.Logical formLearned from8 sentences. Death can be on stairs.Logical formLearned from8 sentences. A (stair case) may pertain-to a person.Logical formLearned from8 sentences.