intro h
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
G H : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
inst✝ : DecidableRel H.Adj
⊢ Disjoint (edgeFinset G) (edgeFinset H) →
    card (edgeFinset G ∪ edgeFinset H) = card (edgeFinset G) + card (edgeFinset H)
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
G H : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
inst✝ : DecidableRel H.Adj
h : Disjoint (edgeFinset G) (edgeFinset H)
⊢ card (edgeFinset G ∪ edgeFinset H) = card (edgeFinset G) + card (edgeFinset H)