@johndcook Nice!

@johndcook Nice!

As you no doubt know, "row" then "column" is fairly conventional e.g. in analogy with a Cayley table... though, I'd say, that analogy really works in your favour if you put a function composition symbol, i.e. "o", in the top left corner. Then we have f o g which is f(g(x)).

Otherwise, one might read "row first" as f(x) and "then column" giving g(f(x)), which is possibly how the original author was thinking about it.