(let ((x1 100) (x2 200) (x3 300) 
         (y1 100) (y2 200) (y3 250) )
     (let* ((comp-props (list 'width 150 'rx 50 'padding 15 'bg-color grey))
            (vn-1 (svg-node rectangular x1 y1 "s1" 'font-size 20)) 
            (vn-2 (svg-node rectangular x1 y2 "s2" 'font-size 20))
            (set-1 (svg-composite-node x3 y1 (some-subgraph "Ca") comp-props))
            (set-2 (svg-composite-node x3 y3 (some-subgraph "Ba") comp-props))
            (edge-1 (svg-edge vn-1 "rc" set-1 "lc" 'arrow "yes"))
            (edge-2 (svg-edge vn-2 "rt" set-1 "lc" 'arrow "yes" 'dy 10))
           )
       (svg-graph (list vn-1 vn-2 set-1 set-2) (list edge-1 edge-2))) )