I admit that I have never had the nerve to use simply in the same sentence as with a set of simultaneous three dimensional second-order partial differential equ

I admit that I have never had the nerve to use simply in the same sentence as with a set of simultaneous three dimensional second-order partial differential equations. Also, see my comment about reciprocal: https://news.ycombinator.com/item?id=22790001 https://news.ycombinator.com/item?id=22790001