$ 'main'
 \                      /---o#
  \-0(!x!)--i-{i}--e{~}<
          /             \
          |             |
          \--------o1---/

$ 'i'
 \                           /-(!q!)(b)a#
  \-1(!b!)0(!c!)--{d}(c)q{~}<
                /            \
@--m(!b!)------/              \
  \--[0001]----(b)(!c!)a1(c)----@
   
  
$ 'd' (dup)
 \-(!d!)(d)(d)#

$ '~'
\
|   /-t-\ #
|  /     \|
\-<       |
   \     /|
    \-f-/ @