関武夫さんという自然を愛している方が生前持っていた森を、ご遺族の方が（財）埼玉県生態系保護協会に寄付したんですね。 Intuitively, the natural range n would be the common house of all sets which have n elements. So, It appears natural to define n being an equivalence class under the relation "could be made in a single to one correspondence". 関さんの森、という言葉の響きが少し面白く感じて... https://bestayurvedicsupplements.food.blog/2025/09/03/cureayu-best-ayurvedic-brand-in-india-for-wellness-remedies/