At Southgate Mall, mattresses are sold only at Mattress Madness.
Evidence
At Southgate Mall, mattresses MS → MM are sold only at Mattress Madness.
Every mattress at Mattress MM → 20 Madness is on sale at a 20 percent discount.
Conclusion
So, every mattress for sale at MS → 20 Southgate Mall is on sale at a 20 percent discount.
Evaluate
This argument infers a conditional relationship from the connection of two different two conditional relationships. This structure is also known as a syllogism.