Dear friends, I'm trying to find a resolution of the three vectors product in geometrical algebra, and there's no book or text that explaines this. The geometrical product of two vectors is defined like this: ab=a·b+a^b Where a·b is the inner product, and a^b is the outer product. a·b = 1/2 (ab+ba) and a^b=1/2 (ab-ba) In the case of three vectors, I have: a^b^c=1/2(abc-cba) where a^b^c is the external product of three vectors. But the question is how to calculate abc. Does anybody knows it???