Heine hypergeometric series | q-hypergeometric series

The modern definition of the q-hypergeometric function is _r ϕ_s[α_1, α_2, ..., α_r β_1, ..., β_s;q, z] congruent sum_(n = 0)^∞ ((α_1 ;q)_n (α_2 ;q)_n ...(α_r ;q)_n)/((β_1 ;q)_n ...(β_s ;q)_n) z^n/(q;q)_n [(-1)^n q^(n 2)]^(1 + s - r) ,

generalized hypergeometric function | q-Pochhammer symbol | q-Saalschütz sum | q-series