  It is tempting to evaluate F2(x,1) and similar univariate specializations of
Appell's functions by evaluating the apparent power series at x=0 straight away
using the Gauss formula for 2F1(1). But this kind of naive evaluation can lead
to errors as the 2F1(1) coefficients might eventually diverge; then the actual
power series at x=0 might involve branching terms. This paper demonstrates
these complications on concrete examples.
