Goal:
  
  G1 : t
  G2 : t
  H : invariants G1
  H0 : invariants G2
  l : labelling
  HGl : correct_labelling G1 l
  embed : full_subgraph G1 G2
  acG2 : acyclic_no_loop G2
  Gl := relabel_on G1 G2 l : t
  l' := to_label ∘ lsp Gl (s Gl) : V.t -> nat
  invGl : invariants (relabel_on G1 G2 l)
  acGl : acyclic_no_sloop (relabel_on G1 G2 l)
  ============================
   (correct_labelling Gl l')


DEBUG:Going to execute:
<coq-core.plugins.ssreflect::ssrapply@0> $1
DEBUG LTAC Evaluated term: (relabel_on_invariants G1 G2 l
                              (edges_sub G1 G2 embed) HGl)
DEBUG LTAC Evaluated term: (acyclic_relabel_on G1 G2 l HGl
                              (lsp_dominate G1 G2 embed))