The frame 1 wherein said parallelogram shaped structure includes a pair of {TAIL ~ retaining cables} having an even, predetermined length and extending one along each of the front and rear of the frame, from said axis to {HEAD ~ a diagonally opposite point} of the parallelogram shaped structure 
The frame 1 wherein said parallelogram shaped structure includes a pair of { TAIL ~ retaining cables } having an even , predetermined length and extending one along each of the front and rear of the frame , from said axis to { HEAD ~ a diagonally opposite point } of the parallelogram shaped structure
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH