Goal:
    A : Type  B : Type  f0 : A → B
  ============================
   (map_In [] (λ (x : A) (_ : In x []), f0 x) = map f0 [])


DEBUG:Going to execute:
done
Level 2: evaluation returns
idtac
where
c := map_In l g
of type
constr of type tacvalue

Level 2: evaluation returns
idtac
where
c := map_In l g
of type
constr of type tacvalue