闭集 (bìjí): closed set (mathematics, topolo…

Meanings

1 closed set (mathematics, topology)

Characters

闭

Examples

闭区间是实数轴上的闭集。

Bìqūjiān shì shíshùzhóu shàng de bìjí.

A closed interval is a closed set on the real number line.

闭集的补集是开集。

Bìjí de bǔjí shì kāijí.

The complement of a closed set is an open set.

Tips

memory

Pair: 开集 (kāijí, 'open set') ↔ 闭集 (bìjí, 'closed set'). The 集 ('set') series is highly productive in math Chinese — 子集 (subset), 空集 (empty set), 并集 (union), 交集 (intersection).

Stroke Order

闭 bì

集 jí

Related Words

闭子集 bìzǐjí

closed subset (mathematics, topology)

闭包 bìbāo

closure (mathematics) — the smallest closed set containing a given set / closure (computer science) — a function bundled together with references to its surrounding state

集合 jíhé HSK 4 #3,792

to gather / to assemble / set (in mathematics)

闭区间 bìqūjiān

closed interval (mathematics)

点集合 diǎnjíhé

point set (mathematics)

封闭 fēngbì HSK 4 #5,678

to close off / to seal / closed / isolated

闭门造车 bìménzàochē

to build a cart behind closed doors (idiom) / to work in isolation, out of touch with reality

闭口 bìkǒu

closed comedone (skincare) / small skin-colored bump under the skin, whitehead

闭 bì HSK 6 #431

to close; to shut / to obstruct; to block

结果集 jiéguǒjí

result set (database query result)