When working with GF in French, the Logical Conditions for a field show 'Tout' and 'Tous' (which both essentially mean 'All'). Instead, it should read of 'Tout' and 'Une' (one).
Actually, I think proper French should have that whole sentence read like this instead:
"Afficher | Cacher " ce champ si "toutes les conditions sont vraies | une des conditions est vraie" :
This has led us to make a mistake recently in building a form for a client, I thought it'd be fixed, but I think someone has to report it for that to happen ;)
BTW, blame French's grammatical plural and grammar rules, but I couldn't find a simple way and use a single word as you do in English for All/One ...