充要条件 chōng yào tiáo jiàn

DEFINITIONS

  1. necessary and sufficient condition

CHARACTERS

充 chōng
HSK 5
fill, be full, supply
要 yào
HSK 2
necessary, essential; necessity
条 tiáo
HSK 2
clause, condition; string, stripe
件 jiàn
HSK 2
numerary adjunct for article; matter