Goal:
  
  x : V.t
  s0 : VSet.t
  s1 : VSet.t
  s2 : VSet.t
  disj20 : Disjoint s2 s0
  disj0' : Disjoint s1 s0
  _a_ : VSet.elt
  eq : VSet.E.eq _a_ x
  ins0 : VSet.In x s1
  _a1_ : VSetProp.Add x s1 s2
  __view_subject__ : ~ VSet.In x s1
  ============================
   (False -> False)


DEBUG:Going to execute:
<coq-core.plugins.ltac::trivial@0> $1 $2

Goals:

DEBUG:Going to execute:
hnf

Goals:

DEBUG:Going to execute:
intros

Goals:

DEBUG:Going to execute:
solve
[ do
![ solve
 [ trivial | apply : eq_sym ; trivial ]
 | discriminate
 | contradiction
 | Ltac.split ]
| case not_locked_false_eq_true; Ltac.assumption
| match goal with
  | H:~ _ |- _ => solve [ case H; trivial ]
  end ]