Goal:
  
  A : Type
  P : list A → list A → A → A → Type
  Γ : list A
  H1 : sigma (λ _ : list A, list A)
  H : All2_fold P (pr1 H1) (pr2 H1)
  ============================
   ({| pr1 := Γ; pr2 := Γ |} = H1
    → let H := CoreTactics.block in
      let H0 := CoreTactics.block in
      All_fold (λ (Γ : list A) (d : A), P Γ Γ d d) Γ)


DEBUG:Going to execute:
move_after_deps id' t; CoreTactics.revert_until id'; rename
            id' into id
Level 3: evaluation returns
move_after_deps id' t; CoreTactics.revert_until id'; rename id' into id;
 cont id'1 id
where
t := {| pr1 := Γ; pr2 := Γ |}
of type
constr
id'1 := H1
of type
constr
id' := H
of type
ident
id := H
of type
ident
cont := fun id id' => DepElim.decompose_exists id id'
        where
        id := H
        of type
        ident
of type
tacvalue of type tacvalue