[refset]

Thank you for the explanations. Do you happen to know why transactions ("transaction requests") are represented as lists and not sets?

[stuarthalloway]

When we designed Datomic (circa 2010), we were concerned that many languages had better support for lists than for sets, in particular list literals and no set literals.

Clojure of course had set literals from the beginning...

[richhickey]

An advantage of using lists is that tx data tends to be built up serially in code. Having to look at your tx data in a different (set) order would make proofreading alongside the code more difficult.