(select
 (bgp
   (triple ?::?60 |http://www.w3.org/1999/02/22-rdf-syntax-ns#|:first ?::?59)
   (triple ?::?60 |http://www.w3.org/1999/02/22-rdf-syntax-ns#|:rest
           |http://www.w3.org/1999/02/22-rdf-syntax-ns#|:nil)
   (triple ?::?59 |http://www.w3.org/1999/02/22-rdf-syntax-ns#|:first ?:z)
   (triple ?::?59 |http://www.w3.org/1999/02/22-rdf-syntax-ns#|:rest
           |http://www.w3.org/1999/02/22-rdf-syntax-ns#|:nil))
 (?:z))