Source code in the icon programming language

procedure do_permute(l, i, n)
    if i >= n then
        return l
    else
        suspend l[i to n] <-> l[i] & do_permute(l, i+1, n)
 end
 
 procedure permute(l)
    suspend do_permute(l, 1, *l)
 end
 
 procedure sorted(l)
    local i
    if (i := 2 to *l & l[i] >= l[i-1]) then return &fail else return 1
 end
 
 procedure main()
    local l
    l := [6,3,4,5,1]
    |( l := permute(l) & sorted(l)) \1 & every writes(" ",!l)
 end