This is probably the most "hackernews" conversation I've ever had but as far as I've ever seen the term used, "memoization" is not restricted to temporarily tab

This is probably the most "hackernews" conversation I've ever had but as far as I've ever seen the term used, "memoization" is not restricted to temporarily tabling the results during a single run of the algorithm but used to mean any caching of results of an expensive pure function for future use. You seem to call that a "semi-permanent database of answers". Here is the original memoization paper [1] where he is using a constant-time table lookup exactly as I envisage in this case rather than only tabling results during a single invocation of the algorithm. Ironically he uses it to memoize a recursively-defined factorial function. [1] https://www.cs.utexas.edu/users/hunt/research/hash-cons/hash-cons-papers/michie-memo-nature-1968.pdf https://www.cs.utexas.edu/users/hunt/research/hash-cons/hash...