Proposed resolution:

This wording is relative to N4910.

1. Modify [range.utility.helpers] as indicated:

   [Drafting note: This change effectively just moves the definitions of require-constant and tiny-range from [range.lazy.split.view] to [range.utility.helpers].]

   […]
   template<class T, class U>
     concept different-from = // exposition only
       !same_as<remove_cvref_t<T>, remove_cvref_t<U>>;
   
   template<auto> struct require-constant; // exposition only
   
   template<class R>
   concept tiny-range = // exposition only
     sized_range<R> &&
     requires { typename require-constant<remove_reference_t<R>::size()>; } &&
     (remove_reference_t<R>::size() <= 1);
   

2. Modify [range.owning.view], class template owning_view synopsis, as indicated:

   […]
   constexpr static auto size() requires tiny-range<R>
   { return R::size(); }
   constexpr auto size() requires sized_range<R>
   { return ranges::size(r_); }
   constexpr auto size() const requires sized_range<const R>
   { return ranges::size(r_); }
   […]
   

3. Modify [range.lazy.split.view], class template lazy_split_view synopsis, as indicated:

   [Drafting note: This change effectively just moves the definitions of require-constant and tiny-range from [range.lazy.split.view] to [range.utility.helpers].]

   namespace std::ranges {
     template<auto> struct require-constant; // exposition only
     
     template<class R>
     concept tiny-range = // exposition only
       sized_range<R> &&
       requires { typename require-constant<remove_reference_t<R>::size()>; } &&
       (remove_reference_t<R>::size() <= 1);
       
     template<input_range V, forward_range Pattern>
       requires view<V> && view<Pattern> &&
                indirectly_comparable<iterator_t<V>, iterator_t<Pattern>, ranges::equal_to> &&
                (forward_range<V> || tiny-range<Pattern>)
     class lazy_split_view : public view_interface<lazy_split_view<V, Pattern>> {
       […]
     };
     […]
   }