noun
: a symbol indicating substitution in turn of each of n given values followed by addition of the results obtained
the umbral symbol a in the expression x a y a which stands for x 1 y 1 +x 2 y 2 +…+x n y n
noun
: a symbol indicating substitution in turn of each of n given values followed by addition of the results obtained
the umbral symbol a in the expression x a y a which stands for x 1 y 1 +x 2 y 2 +…+x n y n
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012