We obtain model independent bounds for the form factors which arise in
semileptonic B → Pi decays. To this end we derive a theoretical restriction
for possible combinations of the value of the form factor and its derivatives
at the endpoint region. These restrictions are then used as an input in a -
slightly modified - general formalism, which has already been deduced and
applied in earlier publications. Our results can be used to set constraints on
the form factors which have to be obeyed by all model dependent
parametrizations.
