Goal:
  
  A : Type
  P : A → A → Prop
  a : A
  l : list A
  a0 : A
  l' : list A
  r : A
  r' : A
  IHl : Forall2 P l l' ∧ P r r'
  H : Forall2 P (a :: l ++ [r]) (a0 :: l' ++ [r'])
  H3 : P a a0
  H5 : Forall2 P (l ++ [r]) (l' ++ [r'])
  ============================
   (Forall2 P (a :: l) (a0 :: l') ∧ P r r')


DEBUG:Going to execute:
<Coq.Init.Tauto.simplif> flags;
            <Coq.Init.Tauto.axioms> flags ||
              match reverse goal with
              | id:(?X1 → ?X2) → ?X3
                |- _ =>
                    Ltac.cut X3;
                     [ intro; clear id; t_tauto_intuit
                     | Ltac.cut (X1 → X2);
                        [ exact
                        id
                        | generalize (λ y : X2, id (λ x : X1, y)); intro;
                           clear id; (solve [ t_tauto_intuit ]) ] ]
              | id:¬ ?X1 → ?X3
                |- _ =>
                    Ltac.cut X3;
                     [ intro; clear id; t_tauto_intuit
                     | Ltac.cut (¬ X1);
                        [ exact
                        id
                        | clear id; intro; (solve [ t_tauto_intuit ]) ] ]
              | |- ?X1 =>
                    <Coq.Init.Tauto.is_disj> flags X1; (solve
                     [ Ltac.left; t_tauto_intuit
                     | Ltac.right; t_tauto_intuit ])
              end ||
                match goal with
                | |- _ → _ => intro; t_tauto_intuit
                | |- _ => t_reduce; t_solver
                end || t_solver