Andrews–Merca and Guo–Zeng's truncated Jacobi triple product conjecture

Let $\ell$, $R$ and $S$ be positive integers with $1\leq S<R/2$, and let $(a;q)_\infty$ denote the $q$-Pochhammer symbol. Andrews–Merca and Guo–Zeng's conjecture. The coefficient of $q^n$, for $n\geq1$, in

$$(-1)^{\ell-1}\frac{\sum_{j=0}^{\ell-1}(-1)^j q^{Rj(j+1)/2-Sj}\left(1-q^{(2j+1)S}\right)}{(q^S,q^{R-S},q^R;q^R)_\infty}$$

is nonnegative. The conjecture was proved analytically by Mao and combinatorially by Yee, so its status is settled.