Goal:
    G : t  s0 : VSet.t  x : V.t  s1 : VSet.t  x0 : V.t
  ============================
   (NoConfusion_SPath
      {|
        pr1 := {| pr1 := s0; pr2 := {| pr1 := x; pr2 := x |} |};
        pr2 := spath_refl s0 x
      |}
      {|
        pr1 := {| pr1 := s1; pr2 := {| pr1 := x0; pr2 := x0 |} |};
        pr2 := spath_refl s1 x0
      |} ->
    let H := CoreTactics.block in
    {|
      pr1 := {| pr1 := s0; pr2 := {| pr1 := x; pr2 := x |} |};
      pr2 := spath_refl s0 x
    |} =
    {|
      pr1 := {| pr1 := s1; pr2 := {| pr1 := x0; pr2 := x0 |} |};
      pr2 := spath_refl s1 x0
    |})


DEBUG:Going to execute:
intro; CoreTactics.intros_until_block