  This document describes Darlin, a succinct zero-knowledge argument of
knowledge based on the Marlin SNARK (Chiesa et al., Eurocrypt 2020) and the
`dlog' polynomial commitment scheme from Bootle et al. EUROCRYPT 2016. Darlin
addresses recursive proofs by integrating the amortization technique from Halo
(IACR eprint 2019/099) for the non-succinct parts of the dlog verifier, and we
adapt their strategy for bivariate circuit encoding polynomials to aggregate
Marlin's inner sumchecks across the nodes the recursive scheme. We estimate the
performance impact of inner sumcheck aggregation by about 30% in a tree-like
scheme of in-degree 2, and beyond when applied to linear recursion.
