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

% DET: points E_a and H_a are not the same

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

Using the point G, the line h_a and the point E_a, construct a line h_G,-1/2(h_a) (rule W15);

Using the line h_G,-1/2(h_a) and the line a, construct a point M_a (rule W03);

% NDG: lines h_G,-1/2(h_a) and a are not parallel

% DET: lines h_G,-1/2(h_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 E_a and the point A, construct a point H (rule W01);

Using the point G and the point H, construct a point O (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