Goal:
  
  A : Type
  B : Type
  C : Type
  D : Type
  E : Type
  P : E → A → Type
  Q : C → A → Type
  R : B → D → Type
  f : B → C → E
  b : B
  l : list B
  l''' : list D
  hb : All2 R (b :: l) l'''
  ============================
   (∀ (H := CoreTactics.block) (x : C) (y : A) (l0 : list C) (l' : list A),
      Q x y
      → All2 Q l0 l'
        → #|l| = #|l0|
          → (∀ (x0 : B) (y0 : C) (z : A) (w : D),
               R x0 w → Q y0 z → P (f x0 y0) z)
            → (∀ (l : list B) (l''' : list D),
                 All2 R l l''' → #|l| = #|l0| → All2 P (map2 f l l0) l')
              → let H0 := CoreTactics.block in
                All2 P (map2 f (b :: l) (x :: l0)) (y :: l'))


DEBUG:Going to execute:
get_signature_pack id id'; hnf in (value of id');
            hnf in (type of id')
Level 3: evaluation returns
get_signature_pack id id'; hnf in (value of id'); hnf in (type of id');
 lazymatch goal with
 | id':=?v:_
   |- context [ id ] =>
       generalize (eq_refl : v = id'); clearbody id'; simpl in id';
        cont id id' id v
 | id':=?v:_
   |- _ =>
       let id'1 := fresh id' in
       let id'2 := fresh id' in
       set (id'2 := pr2 id'); set (id'1 := pr1 id') in id'2;
        hnf in (value of id'1), (value of id'2); try red in (type of id'2);
        match goal with
        | id'1:=?t:_
          |- _ =>
              generalize (eq_refl : t = id'1); clearbody id'2 id'1; clear id'
               id; try unfold signature in id'2; hnf in id'2; 
               simpl in id'2; rename id'2 into id; 
               cont id id id'1 t
        end
 end
where
id' := hb0
of type
intropattern
id := hb
of type
constr
cont := fun id id' id'1 t => try rename id into id',id' into id; cont id'1 id
        where
        id := hb
        of type
        constr
        cont := fun id id' => DepElim.decompose_exists id id'
                where
                id := hb
                of type
                constr
        of type
        tacvalue
of type
tacvalue of type tacvalue

Level 2: evaluation returns
get_signature_pack id id'; hnf in (value of id'); hnf in (type of id');
 lazymatch goal with
 | id':=?v:_
   |- context [ id ] =>
       generalize (eq_refl : v = id'); clearbody id'; simpl in id';
        cont id id' id v
 | id':=?v:_
   |- _ =>
       let id'1 := fresh id' in
       let id'2 := fresh id' in
       set (id'2 := pr2 id'); set (id'1 := pr1 id') in id'2;
        hnf in (value of id'1), (value of id'2); try red in (type of id'2);
        match goal with
        | id'1:=?t:_
          |- _ =>
              generalize (eq_refl : t = id'1); clearbody id'2 id'1; clear id'
               id; try unfold signature in id'2; hnf in id'2; 
               simpl in id'2; rename id'2 into id; 
               cont id id id'1 t
        end
 end
where
id' := hb0
of type
intropattern
id := hb
of type
constr
cont := fun id id' id'1 t => try rename id into id',id' into id; cont id'1 id
        where
        id := hb
        of type
        constr
        cont := fun id id' => DepElim.decompose_exists id id'
                where
                id := hb
                of type
                constr
        of type
        tacvalue
of type
tacvalue of type tacvalue

Level 1: evaluation returns
get_signature_pack id id'; hnf in (value of id'); hnf in (type of id');
 lazymatch goal with
 | id':=?v:_
   |- context [ id ] =>
       generalize (eq_refl : v = id'); clearbody id'; simpl in id';
        cont id id' id v
 | id':=?v:_
   |- _ =>
       let id'1 := fresh id' in
       let id'2 := fresh id' in
       set (id'2 := pr2 id'); set (id'1 := pr1 id') in id'2;
        hnf in (value of id'1), (value of id'2); try red in (type of id'2);
        match goal with
        | id'1:=?t:_
          |- _ =>
              generalize (eq_refl : t = id'1); clearbody id'2 id'1; clear id'
               id; try unfold signature in id'2; hnf in id'2; 
               simpl in id'2; rename id'2 into id; 
               cont id id id'1 t
        end
 end
where
id' := hb0
of type
intropattern
id := hb
of type
constr
cont := fun id id' id'1 t => try rename id into id',id' into id; cont id'1 id
        where
        id := hb
        of type
        constr
        cont := fun id id' => DepElim.decompose_exists id id'
                where
                id := hb
                of type
                constr
        of type
        tacvalue
of type
tacvalue of type tacvalue