Using the point O and the point M_c, construct a line m_c (rule W02);

% DET: points O and M_c are not the same

Using the point H_a and the point M_c, construct a circle k(M_c,A) (rule W06);

% NDG: points H_a and M_c are not the same

Using the point M_c and the line m_c, construct a line c (rule W10a);

Using the circle k(M_c,A) and the line c, construct a point A and a point B (rule W04);

% NDG: line c and circle k(M_c,A) intersect

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

% DET: points H_a and B 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 circle k(O,C), the line a, the point O and the point B, construct a point C (rule W05);

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

% DET: points B and C must be different