The parameter ORIGIN does not work inside a program block.

You're confusing

with

The first is the system variable ORIGIN, which defines the first/starting index for arrays (vectors and matrices).

The second is a(n ordinary) variable ORIGIN, which has NOTHING to do with array indexing.

If you want to define ORIGIN, you must ensure that the identifier is labelled correctly:

Apart from that, you are right to observe that the statement ORIGIN <- 1 (or whatever other value) does not work (as might be expected) in a program. See this:

Note that I use different font settings for the differently labelled items, because that makes life easier, and helps to prevent errors. My program demonstrates that even if ORIGIN is 3, I can still use index 0 for array b.

Now is this a bug? I think not. I think that changing the value of ORIGIN to various values within one sheet should not be done. In the case of your Ft calculation along b, you apparently need i to run from 1 to a value n, so it would be better programmed as:

Finally. It seems as though you are programming a function that is (almost) readily available in Prime.

Check out pnorm():

then

and

Your second function is related to the built-in qnorm():

then

Success!
Luc