(* pl2.m:  S. A. Fulling, Nov. 1995 (first version summer 1994) *)

Off[General::spell1]
Share[]
orderRules = {
   x1^(n1_)*x2^(n2_) :> x1^n2*x2^n1 /; n2 > n1
   }

qmax = 9
max = 2(qmax+1)

link = Sum[t^(2j) c[j] x1^j x2^j, {j, 0, qmax}] +O[t]^max
point1 = Sum[t^(2j) c[j] x1^(2j), {j,0, qmax}] + O[t]^max
point2 = point1 /. x1 -> x2

identity = link * point1 * point2
pl2temp = (Expand[Normal[identity] * x1^2 x2^2] //. 
                                   orderRules)/ (x1^2 x2^2)
pl2 = Collect[pl2temp, Prepend[Table[c[qmax-i], {i,0,qmax}], t]]

pl2point = pl2 //. c[n_] -> 1
pl2line = pl2 //. {x1->1, x2->1}
pl2total = pl2line //. c[n_] -> 1
 
Save["pl2.out", pl2, pl2point, pl2line, pl2total]
Quit[]