Concatenation of a sequence of words

### 4.2.5 Concatenation of a sequence of words

The cumSum command works on strings like it does on expressions by doing partial concatenation (see Section 5.3.26).

- cumSum takes L, a list of strings.
- cumSum(L) returns a sequence of strings where the element of index k is the concatenation of the strings in L with indices 0 to k.

#### Example

cumSum("Hello, ","is ","that ","you?")

“Hello, ”,“Hello, is ”, “Hello, is that ”,“Hello, is that you?” |  |  |  |  |  |  |  |  |  |