Set: pp::colors
  Set: pp::unicode
  Assumed: a
  Assumed: b
  Assumed: f
  Assumed: fNat
(∀ x : ℕ, x > 0) ∧ (∀ x : Bool, f x)
congr1 (∀ x : Bool, f x) (congr2 and (allext (λ x : ℕ, fNat x)))