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

theorem :: SQUARE_1:100
  0 < x/y implies sqrt (x/y) = sqrt |.x.| / sqrt |.y.|
proof
  assume 0 < x/y;
  then x/y = |.x/y.| by Def1;
  then
A1: x/y = |.x.|/|.y.| by COMPLEX1:67;
  0 <= |.x.| & 0 <= |.y.| by COMPLEX1:46;
  hence thesis by A1,SQUARE_1:30;
end;
