Goal:
  
  G : t
  HI : invariants G
  HG : acyclic_no_loop G
  p'' : VSet.t
  p''0 : V.t
  p' : V.t
  p : SPath G p'' p''0 p'
  ============================
   (let H := CoreTactics.block in
    forall (x : V.t) (z : Z) (p0 : SPath G (V G) x (s G)),
    {|
      pr1 := {| pr1 := V G; pr2 := {| pr1 := x; pr2 := s G |} |}; pr2 := p0
    |} =
    {|
      pr1 := {| pr1 := p''; pr2 := {| pr1 := p''0; pr2 := p' |} |}; pr2 := p
    |} ->
    let H0 := CoreTactics.block in
    sweight p0 = z ->
    ~ VSet.In x (V G) -> let H1 := CoreTactics.block in z = 0)


DEBUG:Going to execute:
tac H
DEBUG LTAC Evaluated term: (let H := CoreTactics.block in
                            forall (x : V.t) (z : Z)
                              (p0 : SPath G (V G) x (s G)),
                            {|
                              pr1 :=
                                {|
                                  pr1 := V G;
                                  pr2 := {| pr1 := x; pr2 := s G |}
                                |};
                              pr2 := p0
                            |} =
                            {|
                              pr1 :=
                                {|
                                  pr1 := p'';
                                  pr2 := {| pr1 := p''0; pr2 := p' |}
                                |};
                              pr2 := p
                            |} ->
                            let H0 := CoreTactics.block in
                            sweight p0 = z ->
                            ~ VSet.In x (V G) ->
                            let H1 := CoreTactics.block in z = 0)