hp 28s - creating nested lists

[mbrethen]

Werner,

This code has errors:

Code:

NDUPN
\<<
  -> n
  \<<
    1 2 n
    FOR i
      DUPN i DUP
    STEP
    n - DUP 0 <
    { NEG DUPN }
    { DROPN }
    IFTE
    n
  \>>
\>>

Initially the error traces back to the FOR statement, so I removed the '2'. Then it gives an error on DUPN. I gave up at this point.

This does work:

Code:

NDUPN
\<< 0. OVER START OVER SWAP NEXT ROT ROT DROP2 \>>

But why create a separate program when your original code works? What is the advantage (other than calling it from multiple programs)?