  One-shot achievable rate region for source coding when coded side information
is available at the decoder (source coding with a helper) is proposed. The
achievable region proposed is in terms of conditional smooth max Renyi entropy
and smooth max Renyi divergence. Asymptotically (in the limit of large block
lengths) this region is quantified in terms of spectral-sup conditional entropy
rate and spectral- sup mutual information rate. In particular, it coincides
with the rate region derived in the limit of unlimited independent and
identically distributed copies of the sources.
