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

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

% DET: points H_a and H are not the same

Using the point H_a and the line h_a, construct a line a (rule W10a);

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

Using the line m_a and the line a, construct a point M_a (rule W03);

% NDG: lines m_a and a are not parallel

% DET: lines m_a and a are not the same

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

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