Goal:
    x : V.t  s : VSet.t
  ============================
   (~ VSet.In x (VSet.remove x s))


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

Goals:
    x : V.t  s : VSet.t  y : V.t
  ============================
   ((VSet.In y (VSet.add x s) -> x = y \/ VSet.In y (VSet.remove x s)) /\
    (x = y \/ VSet.In y (VSet.remove x s) -> VSet.In y (VSet.add x s)))

    x : V.t  s : VSet.t
  ============================
   (~ VSet.In x (VSet.remove x s))


DEBUG:Going to execute:
cbv beta zeta in *
Level 1: Backtrace:

Cannot find any non-recursive equality over x.
Level 1: Backtrace:

Cannot find any non-recursive equality over x.
Level 0: Backtrace:

Cannot find any non-recursive equality over x.

Goals:
    x : V.t  s : VSet.t  y : V.t
  ============================
   ((VSet.In y (VSet.add x s) -> x = y \/ VSet.In y (VSet.remove x s)) /\
    (x = y \/ VSet.In y (VSet.remove x s) -> VSet.In y (VSet.add x s)))

    x : V.t  s : VSet.t
  ============================
   (~ VSet.In x (VSet.remove x s))


DEBUG:Going to execute:
VSetDecide.MSetDecideAuxiliary.Logic_eq_to_E_eq

Goals:
    x : V.t  s : VSet.t  y : V.t
  ============================
   ((VSet.In y (VSet.add x s) -> x = y \/ VSet.In y (VSet.remove x s)) /\
    (x = y \/ VSet.In y (VSet.remove x s) -> VSet.In y (VSet.add x s)))

    x : V.t  s : VSet.t
  ============================
   (~ VSet.In x (VSet.remove x s))


DEBUG:Going to execute:
repeat
            match goal with
            | H:_ |- _ => progress change eq with eq in H
            | |- _ => progress change eq with eq
            end