  A continuum formulation of gauge-fixing resolving the Gribov-Singer ambiguity
remains a challenge. Finding a Lagrangian formulation of operational
resolutions in numerical lattice calculations, like minimal Landau gauge, would
be one possibility. Such a formulation will here be constrained by
reconstructing the Dyson-Schwinger equation for which the lattice
minimal-Landau-gauge ghost propagator is a solution. It is found that this
requires an additional term. As a by-product new, high precision lattice
results for the ghost-gluon vertex in three and four dimensions are obtained.
