Yeah, but now that trivial observation has a name that he coined.
And incidentally, what a terrible name. A "hash" (really hash table) is a specific implementation of a map/dictionary. You shouldn't use "hash" to refer to a map based on search trees.
It is interesting that hash is sometimes (incorrectly) used as a synonym or generic name for map/dictionaty/associative array, but Red-Black-Tree, AVL tree, etc. is not.
And incidentally, what a terrible name. A "hash" (really hash table) is a specific implementation of a map/dictionary. You shouldn't use "hash" to refer to a map based on search trees.