Text: Wadi Natrun was one of the most important areas of Egypt in ancient times, primarily because it was the main source of the mineral natron used in the mummification and glassmaking processes.
Entailment: Wadi Natrun was the main source of natron used in both mummification and glassmaking.
Contradiction: Wadi Natrun was one of the least important areas of Egypt, primarily because it was barren.