Section Arg13.
Variable gf : rel13 T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 -> rel13 T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12.
Arguments gf : clear implicits.

Theorem _paco13_fold: forall r,
gf (upaco13 gf r) <13== paco13 gf r.