exact (hYs i).1.subset_ground
case h.e'_3.hs
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
β : Type u_3
f : α → β
hf : InjOn f M.E
Xs : ι → Set β
B : Set α
hB : M.Base B
Is Ys : ι → Set α
hYs : ∀ (i : ι), M.Basis (Is i) (Ys i) ∧ Xs i ∩ f '' B = f '' Is i ∧ Xs i = f '' Ys i
i : ι
⊢ Ys i ⊆ M.E
no goals