theorem
  for s being convergent Complex_Sequence
  holds lim |.-s.| = |.lim s.|
proof
  let s being convergent Complex_Sequence;
  thus lim |.-s.| = |.lim (-s).| by Th27
    .= |.-(lim s).| by COMSEQ_2:22
    .= |.lim s.| by COMPLEX1:52;
end;
