Goal:
  
  G : t
  HI : invariants G
  HG : acyclic_no_loop G
  z : V.t
  x : V.t
  y : V.t
  z0 : V.t
  e0 : EdgeOf G x y
  p : PathOf G y z0
  e : EdgeOf G z0 z
  i : VSet.elt
  IHp : forall e : EdgeOf G z0 z,
        VSet.In i (nodes G (PathOf_add_end p e)) ->
        VSet.In i (nodes G p) \/ i = z0
  ============================
   (VSet.In i (VSet.add x (nodes G (PathOf_add_end p e))) ->
    VSet.In i (VSet.add x (nodes G p)) \/ i = z0)


DEBUG:Going to execute:
<coq-core.plugins.ssreflect::ssrrewrite@0> $1 $2
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 2: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 2: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 2: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 2: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 2: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 2: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 2: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 2: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic (level 1).
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 2: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 1: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.
Level 0: Backtrace:

Tactic failure: because the goal is beyond the scope of this tactic.