Goal:
  
  A : Type
  a : A
  l : list A
  l' : list A
  IHl : ∀ l' : list A, rev (l ++ l') = rev l' ++ rev l
  ============================
   ((rev l' ++ rev l) ++ [a] = rev l' ++ rev l ++ [a])


DEBUG:Going to execute:
<coq-core.plugins.ssreflect::ssrrewrite@0> $1 $2
DEBUG LTAC Evaluated term: rev_cons
DEBUG LTAC Evaluated term: rev_cons