A 'sum' is a sequence of terms joined by addition. A 'product' is a sequence of terms joined by multiplication. Is there a general term for terms joined by a general associative operation, that mathematicians would know? Is it 'sequence'? In Haskell this would be implemented as a fold, but what do you call the thing it acts on? 'Iterable' and 'Enumerable' are too computer-sciencey. It's possible this question has no good answer.
@christianp annoyingly I most often find general group operations discussed as 'in additive notation, sum over' or 'in multiplicative notation, take the product of', regardless that choice of notation is at times arbitrary enough to change repeatedly within the span of a single chapter.