[QuesnayJr]

I was wondering what this meant, so I googled '"rho type" concatenative', and the only hit was this thread.

[lioeters]

Maybe reflective high-order calculus (ρ-calculus). Found this paper, though even the abstract is incomprehensible to me.

https://www.sciencedirect.com/science/article/pii/S157106610...

[adastra22]

The rho type is the aggregate stack effect e.g. (int int — string) will pop two ints off the stack and push a string.