: edge-pvertices ( edge -- pvertices )
    [
      [ start-pvertex>> ] [ end-pvertex>> ] bi over ,         ! push the start pvertex and initialize the while loop
      [ 2dup eq? not ] [ [ next-pvertex>> dup , ] dip ] while ! while loop: push each additional pvertex up to and including the end pvertex
      2drop                                                   ! clear the stack from the while loop
    ] V{ } make ;                                             ! pvertices sequence is now on the stack