Goal:
  
  G : t
  HI : invariants
  HG : acyclic_no_loop
  s : VSet.t
  x : V.t
  H : (Some 0 <= lsp0 s x x)%nbar
  ============================
   ((fun t : Nbar.t => lsp0 s x x = t -> t = Some 0) (lsp0 s x x))


DEBUG:Going to execute:
case x
DEBUG LTAC Evaluated term: (lsp0 s x x)