Using the point O and the point M_a, construct a line m_a (rule W02);

% DET: points O and M_a are not the same

Using the point O and the point M_b, construct a line m_b (rule W02);

% DET: points O and M_b are not the same

Using the point M_a and the line m_a, construct a line a (rule W10a);

Using the point M_b and the line m_b, construct a line b (rule W10a);

Using the line b and the line a, construct a point C (rule W03);

% NDG: lines b and a are not parallel

% DET: lines b and a are not the same

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

Using the point M_b and the point C, construct a point A (rule W01);