There are some: https://fricas.org/api/SetOfMIntegersInOneToN.html https://fricas.org/api/GrayCode.html mabye even more ...
But in principle you only have to produce the numbers 0..2^(N-1) in binary form and filter (index) your set by the 1's (present), 0 absent.. On Monday, 7 April 2025 at 17:51:16 UTC+2 ra...@hemmecke.org wrote: > Why would you make your code so complicated? > > I would simply write: > > T ==> Integer > pwrset(s: List T) : List List T == > empty? s => [[]] > ps: List List T := pwrset rest s > t: T := first s > tps := [cons(t, p) for p in ps] > concat(ps, tps) > > powerSet(l: List T): List List T == sort((x,y)+->#x<#y, pwrset sort l) > > On 4/7/25 17:14, Martin Baker wrote: > > localPowerSets(j:List(S),filter:List(S)->Boolean): List(List S) == > > empty? j => list [] > > Sm := localPowerSets(rest j,filter) > > Sn: List List S := [] > > for x in Sm repeat > > if filter(x) then > > Sn := cons(reverse cons(first j, x),Sn) > > append(Sn, Sm) > > Why do you use "reverse" here? > > Can you tell a reason for this filter function? > > > gradeAndOrder(a:List S,b:List S) : Boolean == > > if #a < #b then return true > > if #a > #b then return false > > for ia in a for ib in b repeat > > if S has OrderedSet then > > if ia < ib then return true > > if ia > ib then return false > > false > > > > powerSetFiltered(j:List(S),filter:List(S)->Boolean):List List S == > > map(reverse,sort(gradeAndOrder,localPowerSets(j,filter))) > > Again, why reverse? > > > powerSet(j:List(S)):List List S == > > powerSetFiltered(j,(x)+-> true) > > If you want this "stand-alone" then you have to write a package with > parameter T around the above code. > > Ralf > > -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to fricas-devel+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/fricas-devel/73f11d40-727f-48ae-96e1-e449aebd87ban%40googlegroups.com.
