theorem Th1:
  for E st E = p`2` holds Meas(p`1,s).p`2 = 1 - Meas(p`1,s).E
proof
  let E such that
A1: E = p`2`;
  [#] Borel_Sets = REAL & REAL \ E = E` by PROB_1:def 7;
  hence thesis by A1,PROB_1:32;
end;
