include ..\Utilitys.pmt

def save
    over over chain ps> swap 0 put >ps
enddef

def permute /# l l -- #/
    len 2 > if
        len for drop
            pop swap rot swap 1 put swap permute
        endfor
    else
        save rotate save rotate
    endif
    swap len if
        pop rot rot 0 put
    else
        drop drop
    endif
enddef

( ) >ps
( ) ( 1 2 3 4 ) permute
ps> sort print