[Retros] Initiation to PGs

[Noam Elkies]

> I've written a small initiation to PGs, [...]


Looks like a neat project.  I think "oddity" is not merely "etrange"
but also a word-play on the mathematical meaning of "odd" (because
it takes an odd number of half-moves to reach a symmetrical position);
it might be asking too much to find a French translation that maintains
this _jeu de mots_...

NDE