Hi EIA.
I'm sure there's someone who can explain it better than me.
But I'll try:
The code '0' is associated with the object type.
Therefore, if '(cdr (assoc 0 en))' returns 'ATTRIB', it means that the object being analyzed is an attribute.
In the database, blocks are always stored in this way: first the main container entity, then the entities that compose it up to an object type 'ENDBLK' that...