case all _ _ _ _ ih => exact ih
L : Language
Δ✝¹ Δ₁ Δ₂ Γ✝ : Sequent L
p✝¹ q✝ r : SyntacticFormula L
C C' : Set (SyntacticFormula L)
Δ Γ : Sequent L
p q : SyntacticFormula L
ss : C ⊆ C'
Δ✝ : List (SyntacticSemiformula L 0)
p✝ : Semiformula L ℕ (0 + 1)
a✝ : Derivation ((Rew.hom Rew.free) p✝ :: Δ✝⁺)
ih : CutRestricted C a✝ → CutRestricted C' a✝
⊢ CutRestricted C a✝ → CutRestricted C' a✝
no goals