Not exactly computer-related, though by now maybe it's been (trans)ported (?)

WFF = Well Formed Formulae
Proof = er 'proof'

Saw this decades ago when a Sociology Prof, Rennaissance kinda guy played these ~ games with his kids. I deemed it not just about logic.. maybe so far as the rudiments of reasoning? (This presumes that a one or two of the tykes might be interested in that direction.)

Dunno about Finnish either, but recall it was made in other languages than Engrish.

I am told recently - that the restricted body-movement, and especially solid-focussed eye-movement of prolonged CRT screen staring, is beginning to manifest in rather odd spinal ailments. Being noticed esp. in kids, but too early to have an Org. formed (or new disease named). I've asked for a few refs.

FWIW.


Ashton