i was asking not about the etymology of pas but if the French use of two negative elements is similar to the other examples. from the little french I know I believe that both "ne" and "pas" are negatives now, so that would be a 'double negative', no?

Yes, today they are a double negative. I was just rhapsodizing on their etymologies. Pas started out as a non-negative.

Ceci n'est pas un seing.