Proposed resolution:

This wording is relative to N4713.

1. Modify [transform.reduce] as indicated:

   template<class InputIterator1, class InputIterator2, class T>
     T transform_reduce(InputIterator1 first1, InputIterator1 last1,
                        InputIterator2 first2,
                        T init);
   

   -?- Effects: Equivalent to:

   return transform_reduce(first1, last1, first2, init, plus<>(), multiplies<>());
   

   template<class ExecutionPolicy,
            class ForwardIterator1, class ForwardIterator2, class T>
     T transform_reduce(ExecutionPolicy&& exec,
                        ForwardIterator1 first1, ForwardIterator1 last1,
                        ForwardIterator2 first2,
                        T init);
   

   -1- Effects: Equivalent to:

   return transform_reduce(std::forward<ExecutionPolicy>(exec), first1, last1, first2, init, plus<>(), 
   multiplies<>());