  Describing the lightest pseudoscalar mesons as bound states of quark and
antiquark within the framework of an instantaneous Bethe-Salpeter formalism
constructed such as to retain (in contrast to Salpeter's equation) as much
information on the relativistic effects provided by the full quark propagator
as conceivable allows for a surprisingly simple implementation of their near
masslessness mandatory for their interpretability as pseudo-Goldstone bosons
related to the spontaneous breaking of the chiral symmetries of quantum
chromodynamics.
