I was trying to get some new kinda of constraints happening and needed some vector math to make it happen, but the explanations from mathematicians all like to explode the matrices into their components and mash them together. That didn’t sit well in my head but this link I was pointed to, is all maxscripts to do the operations of intersecting vectors etc, using functions found in most 3D software. So I found this easier to read than the Oficial expansions. I use houdini but still this is the best set of explanations I have found.