👉 In mathematics, a "hard set" is an infinite sequence of integers that satisfies certain properties. These properties include: 1. The sequence contains no repeating elements. 2. The sum of all elements in the sequence is greater than or equal to 0. 3. For any two consecutive elements, one must be less than the other. For example, consider the following sequence: {4, 8, 9, 15, 20}. This sequence satisfies all three properties because
