The technique of relaxed power series expansion provides an efficient way to
solve equations of the form F = Phi(F), where the unknown F is a vector of power series,
and where the solution can be obtained as the limit of the sequence 0, Phi(0), Phi(Phi(0)), ...
With respect to other techniques, such as Newton's method, two major advantages are
its generality and the fact that it takes advantage of possible sparseness of Phi,
i.e. the computational complexity can be expressed in terms of the expansion order
and the straight-line size of Phi. In our talk, we show how to extend the relaxed
expansion mechanism to more general implicit equations of the form Phi(F)=0.