Using the point M_a and the point G, construct a point A (rule W01);

Using the point H_c and the point A, construct a line c (rule W02);

% DET: points H_c and A are not the same

Using the point H_c and the point M_a, construct a circle k(M_a,B) (rule W06);

% NDG: points H_c and M_a are not the same

Using the circle k(M_a,B), the line c, the point M_a and the point H_c, construct a point B (rule W05);

% NDG: line c and circle k(M_a,B) intersect

% DET: points H_c and B must be different

Using the point B and the point M_a, construct a point C (rule W01);