$
$*********************************************      basics
$
&device -oecho no -g_default device
&dimen -dimen feet kips
&Title block debugging
$
&surface
   block cube
      plane 1/12 -rectan 0/12 10/12 30/12
      plane 3/12 -rectan 0/12 10/12 30/12
   end_block
   block cube2 -loc 0 -4/12 0
      plane 0/12 -rectan 1/12 2/12 20/12
      plane 2/12 -rectan 1/12 2/12 20/12
   end_block
   block cube3 -loc 0 0/12 0
      plane 0/12 -rectan 3/12 4/12 1/12
      plane 2/12 -rectan 3/12 4/12 1/12
   end_block
   union cube2 cube3 cube4
   diffe cube cube4 cube5
   show cube5
     pic front -xg_win 1/12-0.01 1/12+0.01 -shrink -poi -ano yes
   end
   show cube5
     pic front -xg_win 1/12-0.01 1/12+0.01 -shrink -poi -ano yes
   end
   emit cube5 -body
   emit cube5 -piece '-diftype 3d'
end_&surface
$
$
$*********************************************      all done
$
&finish
