have h' := SkewFamily.cls_skewFamily 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
h : M.Skew X Y
⊢ M.Skew (M.cl X) (M.cl Y)
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
h : M.Skew X Y
h' : M.SkewFamily fun i => M.cl (bif i then X else Y)
⊢ M.Skew (M.cl X) (M.cl Y)