  A systematic approach for the model building of Generalized Parton
Distributions (GPDs), based on their overlap representation within the DGLAP
kinematic region and a further covariant extension to the ERBL one, is applied
to the valence-quark pion's case, using light-front wave functions inspired by
the Nakanishi representation of the pion's Bethe-Salpeter amplitudes (BSA).
This simple but fruitful pion's GPD model illustrates the general model
building technique and, in addition, allows for the ambiguities related to the
covariant extension, grounded on the Double Distribution (DD) representation,
to be constrained by requiring a soft-pion theorem to be properly observed.
