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

% DET: points B and H_b are not the same

Using the point H_b and the point N, construct a circle k(N,M_a) (rule W06);

% NDG: points H_b and N are not the same

Using the circle k(N,M_a), the line h_b, the point N and the point H_b, construct a point E_b (rule W05);

% NDG: line h_b and circle k(N,M_a) intersect

% DET: points H_b and E_b must be different

Using the point E_b and the point B, construct a point H (rule W01);

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

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

Using the point B and the point G, construct a point M_b (rule W01);

Using the point H_b and the point M_b, construct a line b (rule W02);

% DET: points H_b and M_b are not the same

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

% NDG: points B and O are not the same

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

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