Goal:
  
  G1 : t
  G2 : t
  H : invariants G1
  H0 : invariants G2
  H1 : acyclic_no_loop G2
  ============================
   (subgraph G1 G2 ->
    is_full_extension G1 G2 ->
    forall x y : VSet.elt,
    VSet.In x (V G1) -> VSet.In y (V G1) -> (lsp G2 x y <= lsp G1 x y)%nbar)


DEBUG:Going to execute:
<coq-core.plugins.ssreflect::ssrmove@1> $1 $2