fix(data/set/intervals/basic): fix a typo (#3680)

src/data/set/intervals/basic.lean

@@ -557,13 +557,13 @@ subset.antisymm (λ x hx, hx.elim (λ hx, lt_of_le_of_lt hx h) and.right) Iio_su
 
 variable {c : α}
 
-lemma Ioo_subset_Ioo_union_Ici : Ioo a c ⊆ Ioo a b ∪ Ico b c :=
+lemma Ioo_subset_Ioo_union_Ico : Ioo a c ⊆ Ioo a b ∪ Ico b c :=
 λ x hx, (lt_or_le x b).elim (λ hxb, or.inl ⟨hx.1, hxb⟩) (λ hxb, or.inr ⟨hxb, hx.2⟩)
 
 @[simp] lemma Ioo_union_Ico_eq_Ioo (h₁ : a < b) (h₂ : b ≤ c) : Ioo a b ∪ Ico b c = Ioo a c :=
 subset.antisymm
   (λ x hx, hx.elim (λ hx, ⟨hx.1, lt_of_lt_of_le hx.2 h₂⟩) (λ hx, ⟨lt_of_lt_of_le h₁ hx.1, hx.2⟩))
-  Ioo_subset_Ioo_union_Ici
+  Ioo_subset_Ioo_union_Ico
 
 lemma Ico_subset_Ico_union_Ico : Ico a c ⊆ Ico a b ∪ Ico b c :=
 λ x hx, (lt_or_le x b).elim (λ hxb, or.inl ⟨hx.1, hxb⟩) (λ hxb, or.inr ⟨hxb, hx.2⟩)