Rho is much like Python, but with an even less verbose syntax.
The 'return value' for a Rho function is whatever is left on the stack(s).
Rho is internally translated to Pi for use in a single Executor that supports continuations natively.
Example:
fun a(b, c)
b + c
assert a(1, 2) == 3
fun d(e)
fun f(g)
g*2
f(e)
assert d(2) == 4
assert exists a
assert exists d
assert !(exists f)
fun h(i,j,k)
a(i, d(j)*k)
assert h(1,2,3) == 16