Section Arg9.
Variable gf : rel9 T0 T1 T2 T3 T4 T5 T6 T7 T8 -> rel9 T0 T1 T2 T3 T4 T5 T6 T7 T8.
Arguments gf : clear implicits.

Theorem paco9_acc: forall
l r (OBG: forall rr (INC: r <9= rr) (CIH: l <9= rr), l <9= paco9 gf rr),
l <9= paco9 gf r.