Goal:
  
  G1 : t
  ext : EdgeSet.t
  x : VSet.elt
  e : EdgeSet.elt
  _a_ : In e (EdgeSet.elements ext)
  _b_ : (x = e..s \/ x = e..t) /\ VSet.In x (V G1)
  ============================
   (EdgeSet.Raw.InT e (EdgeSet.this ext))


DEBUG:Going to execute:
case not_locked_false_eq_true; Ltac.assumption
Level 1: Backtrace:

Not an inductive goal with 1 constructor.
Level 0: Backtrace:

Not an inductive goal with 1 constructor.
Level 0: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.