I wonder how deep the restriction on tags repetitions is hardwired into acedb
Logically, it is sufficient to avoid identical pathes in model trees: the same
tag may appear several times iff different labeled pathes from the root lead to
every occurence of the tag.
The restriction helps to create .ace files: instead of the whole tree, one
needs to use only 'leaf tags'.
The restriction is tiresome in case, for example, of spatial relationships
expressions in a model: one needs separate tags 'inside_yac' and 'contains_yac'
instead of three tags: 'contains', 'inside', and 'yac', 'clone', 'locus', etc.
Is there anybody who is interested in the subject?