direct sum
Mathematics
noun
A set regarded formally as the sum of sets X 1,…,X n, consisting of ordered n-tuples (x 1,…,x n), where x i ∈ X i, and distinguished from a direct product only in the case of an infinite number of sets, the direct sum consisting only of sequences containing a finite number of non-zero elements.
Origin
Early 20th century; earliest use found in Proceedings of the London Mathematical Society.
- rattler-jumping
- rattle sabres
- Rattle, Sir Simon
- rattle-skull
- rattlesnake
- rattlesnake fern
- rattlesnake grass
- rattlesnake herb
- rattlesnake leaf
- rattlesnake master
- rattlesnake orchid
- rattlesnake plantain
- rattlesnake root
- rattlesnake's master
- rattlesnake weed
- rattlesome
- rattle someone's cage (or chain)
- rattle something off
- rattletrap
- rattle-watch
- rattleweed
- rattlewort
- rattling
- rattling cove
- rattling mumper