  Starting from a phenomenologically successful, numerical solution of the
Dyson-Schwinger equation that governs the quark propagator, we reconstruct in
detail the interaction kernel that has to enter the instantaneous approximation
to the Bethe-Salpeter equation to allow us to describe the lightest
pseudoscalar mesons as quark-antiquark bound states exhibiting the (almost)
masslessness necessary for them to be interpretable as the (pseudo) Goldstone
bosons related to the spontaneous chiral symmetry breaking of quantum
chromodynamics.
