Goal:
  
  A : Type
  B : Type
  R : nat → A → B → Type
  n : nat
  x : A
  y : B
  l : list A
  l' : list B
  r : R #|l| x y
  X : All2i_len R l l'
  IHX : All2i R 0 (List.rev l) (List.rev l')
  ============================
   (All2i R #|List.rev l| [x] [y])


DEBUG:Going to execute:
<coq-core.plugins.ssreflect::ssrrewrite@0> $1 $2
Level 0: Backtrace:

No matching clauses for match.
Level 0: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.
Level 1: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.

File "./theories/All_Forall.v", line 3222, characters 49-64:
Warning: Notation List.rev_length is deprecated since 8.20.
Use length_rev instead.
[deprecated-syntactic-definition-since-8.20,deprecated-since-8.20,deprecated-syntactic-definition,deprecated,default]
File "./theories/All_Forall.v", line 3222, characters 49-64:
Warning: Notation List.rev_length is deprecated since 8.20.
Use length_rev instead.
[deprecated-syntactic-definition-since-8.20,deprecated-since-8.20,deprecated-syntactic-definition,deprecated,default]