Goal:
  
  G : t
  HI : invariants
  HG : acyclic_no_loop
  x : VSet.elt
  Hx : VSet.In x (V G)
  z : Z
  H : lsp x (s G) = Some z
  x0 : SPath (V G) x (s G)
  H0 : sweight x0 = z
  H1 : sweight x0 <= 0
  ============================
   (z <= 0)


DEBUG:Going to execute:
<coq-core.plugins.cc::cc@0> $1
DEBUG LTAC Evaluated term: (lsp x (s G))
DEBUG LTAC Evaluated term: (lsp0_spec_eq z H)
DEBUG LTAC Evaluated term: (source_bottom (to_pathOf x0))
DEBUG LTAC Evaluated term: sweight_weight
DEBUG LTAC Evaluated term: sweight_weight