Cluster LF compared to theoretical LFs calculated with an exponent x = −1.6 for the WD progenitor mass function, and various age combinations. Panel a: single age 13 Gyr old population; Panel b: 12% of the population 8 Gyr old, and 88% is 13‘Gyr old; Panel c: 4% of the population is 8 Gyr, 16% is 10 Gyr old, and 80% is 13 Gyr old; Panel d: 8% of the population is 8 Gyr old, 8% is 12 Gyr old, and 84% is 13 Gyr old.