  Systematic errors in the galaxy redshift distribution $n(z)$ can propagate to
systematic errors in the derived cosmology. We characterize how the degenerate
effects in tomographic bin widths and galaxy bias impart systematic errors on
cosmology inference using observational data from the Deep Lens Survey. For
this we use a combination of galaxy clustering and galaxy-galaxy lensing. We
present two end-to-end analyses from the catalogue level to parameter
estimation. We produce an initial cosmological inference using fiducial
tomographic redshift bins derived from photometric redshifts, then compare this
with a result where the redshift bins are empirically corrected using a set of
spectroscopic redshifts. We find that the derived parameter $S_8 \equiv
\sigma_8 (\Omega_m/.3)^{1/2}$ goes from $.841^{+0.062}_{-.061}$ to
$.739^{+.054}_{-.050}$ upon correcting the n(z) errors in the second method.
