Documentation regarding "The Witness Problem" out of date

[mdittmer]

I just tried the code at https://souffle-lang.github.io/aggregates#the-witness-problem

.decl family(name:symbol, age:number)
.decl youngest(name:symbol, age:number)

family("Alissa", 10).
family("Maria", 46).
family("Mark", 50).

youngest(p, n) :- n = min x : family(p, x).

.output youngest

$ souffle witness.dl -D -
---------------
youngest
name    age
===============
Alissa  10
===============

The code does not " a Witness Problem Error" as documented.

[b-scholz]

Aggregates are still very brittle. We would need to refactor the code for aggregates. Would you have time to help?

I would defer fixing the documentation (it is hit and miss what works and what does not work).