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

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

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

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

% DET: points C and H_a are not the same

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

Choose freely a point A on the line h_a (rule WOnline1)

Using the point A and the point C, construct a line b (rule W02);

% DET: points A and C are not the same

Using the circle k(E_c,C), the line b, the point E_c and the point C, construct a point H_b (rule W05);

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

% DET: points C and H_b must be different

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

% DET: points H and H_b are not the same

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

% NDG: lines a and h_b are not parallel

% DET: lines a and h_b are not the same