Goal:
  
  A : Type
  x : A
  xs : list A
  f : A → bool
  H0 : ∀ f0 : A → bool,
         (λ (x : A) (_ : In x xs), f x) = (λ (x : A) (_ : In x xs), f0 x)
         → forallb_InP xs (λ (x : A) (_ : In x xs), f x) = forallb f0 xs
  ============================
   (forallb_InP xs (λ (x : A) (_ : In x xs), f x) = forallb f xs)


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

Goals:
  
  A : Type
  x : A
  xs : list A
  f : A → bool
  H0 : ∀ f0 : A → bool,
         (λ (x : A) (_ : In x xs), f x) = (λ (x : A) (_ : In x xs), f0 x)
         → forallb_InP xs (λ (x : A) (_ : In x xs), f x) = forallb f0 xs
  ============================
   ((λ (x : A) (_ : In x xs), f x) = λ (x : A) (_ : In x xs), f x)

  
  A : Type
  x : A
  xs : list A
  f : A → bool
  H0 : ∀ f0 : A → bool,
         (λ (x : A) (_ : In x xs), f x) = (λ (x : A) (_ : In x xs), f0 x)
         → forallb_InP xs (λ (x : A) (_ : In x xs), f x) = forallb f0 xs
  ============================
   (forallb f xs = forallb f xs)


DEBUG:Going to execute:
easy
DEBUG LTAC Evaluated term: (H0 f)
DEBUG LTAC Evaluated term: (H0 f)

Goals:
  
  A : Type
  x : A
  xs : list A
  f : A → bool
  H0 : ∀ f0 : A → bool,
         (λ (x : A) (_ : In x xs), f x) = (λ (x : A) (_ : In x xs), f0 x)
         → forallb_InP xs (λ (x : A) (_ : In x xs), f x) = forallb f0 xs
  ============================
   ((λ (x : A) (_ : In x xs), f x) = λ (x : A) (_ : In x xs), f x)

  
  A : Type
  x : A
  xs : list A
  f : A → bool
  H0 : ∀ f0 : A → bool,
         (λ (x : A) (_ : In x xs), f x) = (λ (x : A) (_ : In x xs), f0 x)
         → forallb_InP xs (λ (x : A) (_ : In x xs), f x) = forallb f0 xs
  ============================
   (forallb f xs = forallb f xs)


DEBUG:Going to execute:
easy0 || (solve [ intuition eauto  3 with core terms ])