Theorem: ENat.tsum_encard_eq_encard_iUnion (Matroid/ForMathlib/ENatTopology.lean)

State before:
α : Type u_1
β : Type u_2
ι✝ : Type u_3
s✝ : Set α
n : ℕ∞
f g : α → ℕ∞
ι : Type u_4
s : ι → Set α
hI : univ.PairwiseDisjoint s
⊢ ∑' (i : ι), (s i).encard = (⋃ i, s i).encard
Tactic:
simp_rw [← ENat.tsum_one', ENat.tsum_iUnion_eq_tsum _ _ hI]
State after:
no goals