  We derive upper and lower bounds on the reliability function for the
common-message discrete memoryless broadcast channel with variable-length
feedback. We show that the bounds are tight when the broadcast channel is
stochastically degraded. For the achievability part, we adapt Yamamoto and
Itoh's coding scheme by controlling the expectation of the maximum of a set of
stopping times. For the converse part, we adapt Burnashev's proof techniques
for establishing the reliability functions for (point-to-point) discrete
memoryless channels with variable-length feedback and sequential hypothesis
testing.
