We're also super stoked about getting topology and equations together in the same file (and even code-base!)
The equation solver is soon on our roadmap: https://atopile.io/roadmap/#language-features
The equation solver is soon on our roadmap: https://atopile.io/roadmap/#language-features
https://solvespace.com/index.pl
It's what underlies the geometric constraint solver which you don't need for what you're doing. It's probably worth a look under the hood. You might also read this post from Michael-F-Bryan implementing something similar in Rust:
https://users.rust-lang.org/t/geometric-constraint-solvers-p...
He based his work on what he learned from Solvespace.