Goal:
  
  G : t
  s : VSet.t
  x : V.t
  p : SPath G s x x
  y : VSet.elt
  yinp : VSet.In y (snodes G p)
  rx := spath_refl G VSet.empty x : SPath G VSet.empty x x
  disj : Disjoint s VSet.empty
  ============================
   (exists c : SPath G s y y, sweight c = sweight p)


DEBUG:Going to execute:
<coq-core.plugins.ssreflect::ssrcase@0> $1 $2
DEBUG LTAC Evaluated term: VSet.inter_spec
DEBUG LTAC Evaluated term: (iffLR
                              (Q:=VSet.In _a_ s /\ VSet.In _a_ VSet.empty)
                              (VSet.inter_spec s VSet.empty _a_)
                              _view_subject_)
DEBUG LTAC Evaluated term: VSet.empty_spec
DEBUG LTAC Evaluated term: (VSet.empty_spec _view_subject_)