  In 1944 Dyson defined the rank of a partition as the largest part minus the
number of parts, and conjectured that the residue of the rank mod 5 divides the
partitions of 5n+4 into five equal classes. This gave a combinatorial
explanation of Ramanujan's famous partition congruence mod 5. He made an
analogous conjecture for the rank mod 7 and the partitions of 7n+5. In 1954
Atkin and Swinnerton-Dyer proved Dyson's rank conjectures by constructing
several Lambert-series identities basically using the theory of elliptic
functions. In 2016 the author gave another proof using the theory of weak
harmonic Maass forms. In this paper we describe a new and more elementary
approach using Hecke-Rogers series.
