obtain ⟨B, hB, hBXs⟩ := h
ι : Type u_1
α : Type u_2
M : Matroid α
B I J X X' Y Y' F : Set α
Xs Ys Js Is : ι → Set α
i j : ι
e f : α
η : Type u_3
h : M.ModularFamily Xs
t : η → ι
⊢ M.ModularFamily (Xs ∘ t)
case intro.intro
ι : Type u_1
α : Type u_2
M : Matroid α
B✝ I J X X' Y Y' F : Set α
Xs Ys Js Is : ι → Set α
i j : ι
e f : α
η : Type u_3
t : η → ι
B : Set α
hB : M.Base B
hBXs : ∀ (i : ι), M.Basis (Xs i ∩ B) (Xs i)
⊢ M.ModularFamily (Xs ∘ t)