simp only [decide_eq_true_eq]
α : Type u
β : Type v
inst✝³ : BishopFin α
inst✝² : BishopFin β
p q : α → Prop
inst✝¹ : DecidablePred p
inst✝ : DecidablePred q
⊢ List.countP (fun a => decide ¬decide (p a) = true) (elems α) = count fun a => ¬p a
α : Type u
β : Type v
inst✝³ : BishopFin α
inst✝² : BishopFin β
p q : α → Prop
inst✝¹ : DecidablePred p
inst✝ : DecidablePred q
⊢ List.countP (fun a => decide ¬p a) (elems α) = count fun a => ¬p a