Proposed resolution:

This wording is relative to N5032.

1. Modify [mdspan.syn] as follows:

   // [mdspan.sub], submdspan creation
   template<class OffsetType, class LengthType, class StrideType>
     struct strided_slice;
   
   template<class LayoutMapping>
     struct submdspan_mapping_result;
   
   struct full_extent_t { explicit full_extent_t() = default; };
   inline constexpr full_extent_t full_extent{};
   
   template<class IndexType, size_t... Extents, class... SliceSpecifiers>
     constexpr auto submdspan_extents(const extents<IndexType, Extents...>&, SliceSpecifiers...);
   
   // [mdspan.sub.canonical], submdspan slice canonicalization
   template<class IndexType, size_t... Extents, class... Slices>
     constexpr auto submdspan_canonicalizecanonical_slices(const extents<IndexType, Extents...>& src,
                                                  Slices... slices);
   

2. Modify [mdspan.sub.canonical] as follows:

   `submdspan` slice canonicalization

   template<class IndexType, size_t... Extents, class... Slices>
     constexpr auto submdspan_canonicalizecanonical_slices(const extents<IndexType, Extents...>& src,
                                                  Slices... slices);
   

3. Modify [mdspan.sub.extents] as follows:

   [mdspan.sub.extents] submdspan_extents function

   template<class IndexType, size_t... Extents, class... SliceSpecifiers>
     constexpr auto submdspan_extents(const extents<IndexType, Extents...>& src,
                                      SliceSpecifiers... raw_slices);
   

   -1- Let `slices` be the pack introduced by the following declaration:

     auto [...slices] = submdspan_canonicalizecanonical_slices(src, raw_slices...)
   

4. Modify [mdspan.sub.map.sliceable] as follows:

   -5- Returns: An object `smr` of type `SMR` such that

   • -5.1- smr.mapping.extents() == submdspan_extents(m.extents(), valid_slices...) is `true`; and
   • -5.2- […]

5. Modify [mdspan.sub.map.common] as follows:

   -5- Let `sub_ext` be the result of submdspan_extents(extents(), slices...) and let `SubExtents` be `decltype(sub_ext)`.

6. Modify [mdspan.sub.sub] as follows:

   -2- Let `slices` be the pack introduced by the following declaration:

     auto [...slices] = submdspan_canonicalizecanonical_slices(src, raw_slices...)
   

Rename `submdspan_extents` to `subextents` and `submdspan_canonicalize_slices` to `canonical_slices`.