true !Pho.Listen
  all\# 1 gt
  {
   Tree.Last !\ _\\ 6 left -2 left
   dup numeric
   {
    !Pshop.Slc
   }
   {
    pop 0 !Pshop.Slc
   } ifelse
  }
  {
   0 !Pshop.Slc
  } ifelse
%
% switching to listen mode
%
  6 *pshpdskr
  *cheklstn(
  *psa(