[Retros] Min dual-free SPG where each survivor has moved.

[Andrew Buchanan]

Noam Elkies originally asked for a dual-free SPG in which every unit moved. 
Eric Angelini claimed an SPG in 14.0 in which every *surviving* unit moved.

Here is a dual-free SPG in 13.5 in which every *surviving* unit moved (proof 
by Euclide 0.91). It is easy to see that the task cannot be satisfied in 
fewer moves. 

5rk1/1BQnbR2/5np1/8/2P1P3/2N5/4Nrq1/2KR4
(9+8) SPG in 13.5. 

Enjoy!
Andrew Buchanan