; dl > dt > a.external¬                                                          
 (define (+chain+ node)¬                                                          
   (and-> node¬                                                                   
     (dom:find-self   (node-type? 'a))¬                                           
     (dom:find-self   (node-attr? 'class (cut string=? <> "external")))¬          
     (dom:find-parent (node-type? 'dt) 1)¬                                        
     (dom:find-parent (node-type? 'dl) 1)¬                                        
   )¬                                                                             
 )¬