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

% DET: points M_a and H_a are not the same

Using the point M_a and the line a, construct a line m_a (rule W10b);

Choose freely a point O on the line m_a (rule WOnline2)

Using the point H_a and the line a, construct a line h_a (rule W10b);

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

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 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