Create a sane looking upper level for phenio, independent of the upper level alignment of the source ontologies

[matentzn]

To create a sane looking upper level for phenio, independent of the upper level alignment of the source ontologies, we likely have to iterate.

Upper-level alignment and metaclasses are somewhat similar here, and I feel inclined to keep the metaclasses (bl:has_category bl:Gene) while aligning the upper level manually at the same time. As a first pass, I would:

1. Document all the main categories we need for Monarch, and identify the top level classes (UBERON, MONDO, CL, GO, etc)
2. Document these top-level classes carefully in a documentation page
3. At release time, remove all their parents. This will, in particular, remove basically all of BFO.

[matentzn]

This should be our next big priority