"I see that there is a description of double sca..."

So to reverse a vector, just scale it by $~$-1$~$\. This can be combined with the product rule for scalars to scale a vector by any negative number\!

I see that there is a description of double scaling above. I assume that this is what "the product rule" refers to, but it is never explicitly labeled as such. Maybe giving the paragraph above Reverse a bold heading titled "The Product Rule" would help with this.