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

Choose freely a point A on the line b (rule WOnline2)

Using the point A and the point M_b, construct a point C (rule W01);

Choose freely a point B on the circle k(O,C) (rule WOncircle)