No, maybe I didn't make myself clear.
In Home view I cannot create anything like
g(x):=x^2-x-1
but I can do that in CAS view.
Result (x)->(x^2-x-1).
Now, I can call the numerical solver, e.g.,
nSolve(g(x),x)
Result -.618...
Mem shows CAS Vars, g (Function)
The "Vars" key also shows g in CAS Vars ("All" and "Program").
However, g is gone, once I clear the CAS history. :((
(The reason I need to define g in CAS and not in Home is because a function defined in Home cannot be used with int, solve, nSolve, etc.).
I hope this is clearer now.