PMDs of CHXR 32 from the relative and absolute astrometric measurements for separation (left) and position angle (right). The upper panels refer to the centre of mass of the pair B/C (adopting that the mass of B is 1.5 times that of C), relative to the main component A. The separation PMD rejects here the background hypothesis. The lower panels are PMDs of C relative to B, assuming that the proper motion of B is identical to that of A. Here the background hypothesis is excluded by the position angle PMD.