Goal:
  
  G : t
  s0 : VSet.t
  s' : VSet.t
  x : V.t
  y : V.t
  z : V.t
  p : SPath s0 x y
  t0 : VSet.t
  t1 : V.t
  hin : Disjoint t0 s'
  ============================
   (VSet.Subset s' (VSet.union t0 s'))


DEBUG:Going to execute:
clear H
Level 1: Backtrace:

Proof is not complete.
Level 1: Backtrace:

Proof is not complete.
Level 1: Backtrace:

Proof is not complete.
Level 2: Backtrace:

Proof is not complete.
Level 1: Backtrace:

Proof is not complete.
Level 1: Backtrace:

Proof is not complete.
Level 1: Backtrace:

Proof is not complete.