Goal:
  
  P : elt -> elt -> Prop
  s : t
  H : forall v1 v2 : elt, In v1 s -> In v2 s -> P v1 v2
  x : elt
  H0 : In x s
  ============================
   (elt -> Prop)


DEBUG:Going to execute:
exact (id0 id1)
DEBUG LTAC Evaluated term: (elt -> Prop)