show fsubst ‹a₁ ≃ a₂› (ctx.ind_diff a₁) ≃ ctx.ind_diff a₂
ℕ : Type
inst✝¹ : Natural ℕ
motive : Difference ℕ → Sort u
inst✝ : IndexedFamily motive
ctx : Induction.Context motive
n₁ m₁ n₂ m₂ : ℕ
a₁ : Difference ℕ := n₁——m₁
a₂ : Difference ℕ := n₂——m₂
x✝ : a₁ ≃ a₂
⊢ fsubst x✝ (Induction.Context.ind_diff ctx (n₁——m₁)) ≃ Induction.Context.ind_diff ctx (n₂——m₂)
ℕ : Type
inst✝¹ : Natural ℕ
motive : Difference ℕ → Sort u
inst✝ : IndexedFamily motive
ctx : Induction.Context motive
n₁ m₁ n₂ m₂ : ℕ
a₁ : Difference ℕ := n₁——m₁
a₂ : Difference ℕ := n₂——m₂
x✝ : a₁ ≃ a₂
⊢ fsubst x✝ (Induction.Context.ind_diff ctx a₁) ≃ Induction.Context.ind_diff ctx a₂