DurfeeSquare
The side of the Durfee square: the largest d with at least d parts of size at least d.
DurfeeSquare(partition)
Details
- Defined over `IntegerPartition` as an expression in `_x`, evaluated by compute-engine — the definition IS the implementation.
- Takes a `IntegerPartition` and nothing else — it reads values against their positions, or walks the orbits, so it needs the bijection. Applying it to a bare list is a type error, not a wrong answer.