The following line in action made me reflect:
sig application-data : Map AppDataValueHash (BitString, DeletionCriterion)
contains a map of hashes and openings of various data needed to verify resource logic proofs. The deletion criterion field is described here. The openings are expected to be ordered.
Namely in two spots:
- Why not use the word preimage instead of opening?
- What is an ordered opening for the map data structure
Preimage vs Opening
In the context of hashes, we say a is an opening of a hash h: Hash if h = hash(a).
Isn’t this just the preimage of the hash?
In particular I saw opening used in the definition of an action.
Whereas I’ve seen preimage used in the resource definition.
If they are indeed the same and I’m not misunderstanding what a preimage is, then maybe we should just use preimage in general?
Ordering
what does it mean for the openings to be ordered here. Are the hashes also ordered? what is the criteria? I’m unsure of what this section is trying to communicate.