Sub:
[[유한합,finite_sum]]
[[무한합,infinite_sum]]
{
구체수학 02.합.07.무한합 - 기계인간 John Grib
https://johngrib.github.io/wiki/study/concrete-math/02-sums-07/
}

표현
sum
summation

Compare:
[[direct_sum]]
 https://encyclopediaofmath.org/wiki/Direct_sum
[[곱,product]]