{ print spaces; in:n }
[[$0>][" " 1-]#%]w:

{ left shift; in:x,y out:x<<y }
[[$0>][\2*\ 1-]#%]l:

1 4 l;!       { SIZE = 1<<4 }

$             { y = SIZE }
[$0>]         { y > 0 }
[1-
 $w;!
 1ø           { x = SIZE }
 [$0>]
 [1-
  1ø$2ø\-&0=  { !((x - y) & y) }
   $ ["* "]?
   ~ ["  "]?
 ]#%
 10,
]#%%