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

% NDG: points H_a and N are not the same

Choose freely a point E_c on the circle k(N,M_a) (rule WOncircle)

Using the point E_c and the point N, construct a line m(H_bH_a) (rule W02);

% DET: points E_c and N are not the same

Using the circle k(N,M_a), the line m(H_bH_a), the point N and the point E_c, construct a point M_c (rule W05a);

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

% DET: points E_c and M_c must be different

Using the point H_a and the point E_c, construct a circle k(E_c,C) (rule W06);

% NDG: points H_a and E_c are not the same

Using the circle k(N,M_a), the circle k(E_c,C), the point H_a, the point N and the point E_c, construct a point H_b (rule W08);

% NDG: circles k(N,M_a) and k(E_c,C) intersect

% DET: circles k(N,M_a) and k(E_c,C) are not the same points H_a and H_b must be different

Choose freely a point A on the circle k(M_c,A) (rule WOncircle)

Using the point A and the point M_c, construct a point B (rule W01);

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

% DET: points A and H_a are not the same

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

% DET: points H_b and B are not the same

Using the line h_a and the line h_b, construct a point H (rule W03);

% NDG: lines h_a and h_b are not parallel

% DET: lines h_a and h_b are not the same

Using the point E_c and the point H, construct a point C (rule W01);