arc(r_0019_0003__are,r_0019_0001__These_r_0019_0002__guns,arg0).
arc(r_0019_0003__are,r_0019_0007__defence_r_0019_0008__system,prd).
arc(r_0019_0007__defence_r_0019_0008__system,r_0019_0004__the_r_0019_0005__planets,gen).

( (IP-MAT (NP-SBJ;{LIMPET} (D These;{these})
                           (NS guns;{gun}))
          (BEP;~Ln are;{be})
          (NP-PRD (NP-GEN;{PLANET} (D the;{the})
                                   (NS planets;{planet})
                                   (GENM <apos>))
                  (N defence;{defence})
                  (N system;{system}))
          (PUNC .))
  (ID 19_a_thrust))