reserve X for set;
reserve k,m,n for Nat;
reserve i for Integer;
reserve a,b,c,d,e,g,p,r,x,y for Real;
reserve z for Complex;

theorem
  lim Basel-seq1 = PI^2/6 = lim Basel-seq2
  proof
    lim(p(#)rseq(2,0,2,1)) = p*lim(rseq(2,0,2,1)) by SEQ_2:8;
    hence lim Basel-seq1 = PI^2/6 by Lm17,Lm18,SEQ_2:15;
    lim(p(#)rseq(2,0,2,1)) = p*lim(rseq(2,0,2,1)) by SEQ_2:8;
    hence thesis by Lm17,Lm19,SEQ_2:15;

  end;
