Goal:
    A : Type  a : A  l : list A  IHl : rev (rev l) = l
  ============================
   (a :: rev (rev l) = a :: l)


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