The sequence of EA s found between two consecutive children of . The first term corresponds to one EA , and the second one to two EA s. For the latter case, the Z in the Prod stands for the lefmost point of the second EA . The component of interest here is edges. We are interested in the average number of edges in a connected graph.
Every arch is an edge, plus the original edges to the children.
Thus we distinguish these as EA and conseq . Unfortunately rsolve cannot solve the recurrence relation which gfun gives it. So that we just have to rewrite the previous grammar by adding a new symbol which makes this substitution. Next, we handle components. Each occurrence of comp marks a new component.