Man pages matching name std::ranges::not_equal_to in section 3cxx:

std::ranges::not_equal_to.3cxx.en	debian 12 / libstdc++-12-doc
std::ranges::not_equal_to.3cxx.en	debian 13 / libstdc++-12-doc
std::ranges::not_equal_to.3cxx.en	debian 13 / libstdc++-13-doc
std::ranges::not_equal_to.3cxx.en	debian 13 / libstdc++-14-doc