保长对应 bǎo cháng duì yìng

DEFINITIONS

  1. (math.) distance-preserving correspondence
  2. isometry

CHARACTERS

保 bǎo
HSK 4
protect, safeguard, defend, care
长 cháng
HSK 2
long; length; excel in; leader
对 duì
HSK 1
correct, right; facing, opposed
应 yìng
HSK 3
should, ought to, must