Goal:
    G : t  H : invariants G  x : V.t  y : V.t  e : EdgeOf G x y
  ============================
   (VSet.In (x, e.π1, y)..s (V G) ->
    VSet.In (x, e.π1, y)..t (V G) -> VSet.In x (V G))


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 ]