Dictionary <List <_>> qualifies as a semi-persistent?

Question

In Extended Abstraction: Functional Derivation from Warren Abstract Machine , Maciej Pir'og and Jeremy Gibbons describe the data structure as semi-permanent [7], "if we can revert to previous versions, but we never save two different modifications (siblings) of that same ancestor. " Suppose the object is dict : System.Collections.Dictionary<A, FSharp.Collections.List<B>> . Let the values ​​in the dictionary represent states related to specific keys. Would dict effective semi-persistent state tracking mechanism, assuming only one such Dictionary ? Is this guaranteed by variability of the Dictionary type in combination with sequences of previous states?

Answer 1

It is difficult (to parse, no less the answer) - please note: this is in my understanding of the abstract given ... The answer will be Yes And No. The key here is to use, not structure. The dictionary itself is persistent. Like authors, you can use it semi-permanently. However, having status values ​​on the list can be a little worrisome, as you might be tempted to keep your siblings (again, in use).

For a better understanding - go to the source:
https://www.lri.fr/~conchon/publis/spds-esop08.pdf