sequence ``f(0), f(1), ...``. But, this effect can be achieved in Python
by combining :func:`map` and :func:`count` to form ``map(f, count())``.
-The tools also work well with the high-speed functions in the :mod:`operator`
-module. For example, the plus-operator can be mapped across two vectors to
-form an efficient dot-product: ``sum(map(operator.add, vector1, vector2))``.
+These tools and their built-in counterparts also work well with the high-speed
+functions in the :mod:`operator` module. For example, the multiplication
+operator can be mapped across two vectors to form an efficient dot-product:
+``sum(map(operator.mul, vector1, vector2))``.
**Infinite Iterators:**