direct sum
Mathematical term used in linear algebra and abstract algebra. Refers to a construction that combines modules, vector spaces, or groups. The cross-reference to 和 (sense 1) indicates a relationship to the general concept of 'sum'.
See also: 和
Consider the direct sum of vector spaces.
この定理は直和分解に関するものだ。
This theorem is about direct sum decomposition.
direct sum (of sets)
Compound of 直 (direct) and 和 (sum), a calque from English 'direct sum'.