The elliptical amphitheater's 22,000 seats sell out months in advance for summertime open-air productions of Aida. 
Aida is a popular show, especially in the summer.
mnli hypothesis: Aida is a popular show, especially in the summer. premise: The elliptical amphitheater's 22,000 seats sell out months in advance for summertime open-air productions of Aida. 