Changes from Mercurial (hg https://foss.heptapod.net/isa-afp/afp-devel/ default)
Summary
- Merged
- Disambiguate sufficiently many facts in locales so as to permit a top-level interpretation of ZFC_set_cat.
- Fix a typo.
- Neater links
- Relational_Disjoint_Set_Forests: variant abstraction