Goal:
  
  x : V.t
  p : VSet.t
  H : VSet.In x p -> False
  a : V.t
  H0 : x = a -> False
  H1 : VSet.In a p
  ============================
   (x = a)


DEBUG:Going to execute:
autorewrite with set_eq_simpl in *
Level 3: Backtrace:

No matching clauses for match.