theorem
  Basel-seq1.n = (PI^2/6) * (2*n/(2*n+1)) * ((2*n-1)/(2*n+1))
  proof
A1: (p(#)rseq(2,0,2,1)).n = p*rseq(2,0,2,1).n by VALUED_1:6;
    rseq(2,0,2,1).n = (2*n+0)/(2*n+1) & rseq(2,-1,2,1).n = (2*n-1)/(2*n+1)
       by Th5;
    hence thesis by A1,VALUED_1:5;
  end;
