List Commands Library for 50g

[John Keith]

(07-22-2017 10:49 PM)DavidM Wrote:  Karl-Ludwig Butte recently posted an interesting article discussing the history of the "power set". It appeared to me that there was a close correlation with his demonstration of creating a power set for { 1 2 3 } and the output of the DOCOMB command run with increasing combination choices. I'm not sure if the ordering ends up being exactly the same for larger lists (I haven't tried to input his program to run a comparison), but the following should at least generate the same group of combinations for a given input list:

Code:

\<<
  DUP SIZE \-> list sz \<<
    { }
    1 sz FOR N
      list N \<< \>> DOCOMB
      EVAL
    NEXT
    2 sz ^ \->LIST
  \>>
\>>

Unless I'm mistaken, the Goferlists function Subs also does this. It remains to compare the three programs as to the order of the permutations in the output list.

John