Using the point M_a and the point G, construct a point A (rule W01);

Using the point G and the point H, construct a point O (rule W01);

Using the point M_a and the point O, construct a line m_a (rule W02);

% DET: points M_a and O are not the same

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

% NDG: points A and O are not the same

Using the point M_a and the line m_a, construct a line a (rule W10a);

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

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