Idempotent partition around median of 5?

[Andrei Alexandrescu via Digitalmars-d]

On 02/04/2016 03:30 PM, Timon Gehr wrote:
> At most 6 comparisons, <=3 swaps, idempotent (optimal number of swaps):

What is the minimum number of comparisons? Thx! -- Andrei
P.S. The sythesized searcher is genius.