Goal:
  
  A : Type
  B : Type
  x : A
  xs : list A
  f0 : A → B
  H : ∀ f : A → B,
        (λ (x : A) (_ : In x xs), f0 x) = (λ (x : A) (_ : In x xs), f x)
        → map_In xs (λ (x : A) (_ : In x xs), f0 x) = map f xs
  ============================
   (map_In (x :: xs) (λ (x0 : A) (_ : In x0 (x :: xs)), f0 x0) =
    map f0 (x :: xs))


DEBUG:Going to execute:
match goal with
           | hyp:context [ CoreTactics.block ]
             |- _ =>
                 cbn beta in hyp; eqns_specialize_eqs_block hyp;
                  cbn[eq_rect_r eq_rect] in hyp
           end
Level 1: Backtrace:

No matching clauses for match.

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

  
  A : Type
  B : Type
  x : A
  xs : list A
  f0 : A → B
  H : ∀ f : A → B,
        (λ (x : A) (_ : In x xs), f0 x) = (λ (x : A) (_ : In x xs), f x)
        → map_In xs (λ (x : A) (_ : In x xs), f0 x) = map f xs
  ============================
   (map_In (x :: xs) (λ (x0 : A) (_ : In x0 (x :: xs)), f0 x0) =
    map f0 (x :: xs))


DEBUG:Going to execute:
tac c
Level 1: Backtrace:

No matching clauses for match.

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

  
  A : Type
  B : Type
  x : A
  xs : list A
  f0 : A → B
  H : ∀ f : A → B,
        (λ (x : A) (_ : In x xs), f0 x) = (λ (x : A) (_ : In x xs), f x)
        → map_In xs (λ (x : A) (_ : In x xs), f0 x) = map f xs
  ============================
   (map_In (x :: xs) (λ (x0 : A) (_ : In x0 (x :: xs)), f0 x0) =
    map f0 (x :: xs))


DEBUG:Going to execute:
idtac