[P] = p{-10.0, 70.0} + r{-50.0, 50.0} * te{0.0, 100.0};
[Q] = q{-20.0, 20.0} + s{-50.0, 50.0} * t;
R = r;
[S] = s;
hello =+hello
[S] = s{  };
