reserve x, y, z, r, s, t for Real;

theorem
  0 <= r + |.r.|
proof
A1: 0 <= |.r.| by COMPLEX1:46;
  |.r.| + |.r.| = r + |.r.| or |.r.| + r = -r + r by Def1;
  hence thesis by A1;
end;
