Using the point M_b and the point G, construct a point B (rule W01);

Using the point O and the point M_b, construct a line m_b (rule W02);

% DET: points O and M_b are not the same

Using the point B and the point O, construct a circle k(O,C) (rule W06);

% NDG: points B and O are not the same

Using the point M_b and the line m_b, construct a line b (rule W10a);

Using the circle k(O,C) and the line b, construct a point C and a point A (rule W04);

% NDG: line b and circle k(O,C) intersect