Re: Avoid treating the stack as an array [Re: "Back & Forth" is back!]

Hi,
In fuzzy logic, a triangular membership function mf(x;a,b,c) is defined
as:
mf(x;a,b,c) = (x-a)/(b-a) for a <= x < b,
              (c-x)/(c-b) for b <= x < c,
              0e elsewere.
defining it with locals:
: tri_mf() { f: x f: a f: b f: c } ( f: x a b c -- mv)
     x a f>= x b f< and if x a f- b a f- f/ exit then
     x b f>= x c f< and if c x f- c b f- f/ exit then
     0e
;
But defining it without locals ????!!!!!
: tri_mf() ( f: x a b c -- mv) ....
How?
Ahmed