Suggestions on syntax to express mathematical formula concisely

Question

I am developing functional domain specific embedded language within C++ to translate formulas into working code as concisely and accurately as possible.

I posted a proto

Answer 1

I don't like the way you specify that "triangular" 2d range. I'd like to see something like:

(i,j) in range(0..j,0..N)

for example, which could then lead to:

X = sum(f(i,j) for (i,j) in range(0..j,0..N));

AFAIK This is not an existing language, but since you're creating your own syntax... I'm doubtful about the ability to use j in the range expression for i, but you found a way in yours :-)