Erdős also came up with the Erdős sum, a 'score' you can calculate for any primitive set. He showed that the sum had a maximum possible value—and conjectured that this value must hold only for the set of all prime numbers.
这里提供了数学概念的具体量化指标。'最大可能值'的表述暗示了有明确的数学界限，但文章未提供具体数值。这反映了数学中某些概念虽然可量化，但具体数值可能需要更专业的数学背景才能理解，体现了数学研究的抽象性。