olemus
(1) matemaatikas
(1a) tsükliteta graaf: sidus mets on puu
Wiktionary:
4. (graph theory) a graph with no cycles; i.e., a graph made up of trees
https://image.slidesharecdn.com/graphs1-130126021226-phpapp01/95/graphs-in-data-structure-11-638.jpg

(1b) sellise graafiga esitatav andmestruktuur
http://orion.lcg.ufrj.br/Dr.Dobbs/books/book9/images/fig3_29.gif
https://en.wikipedia.org/wiki/Disjoint-set_data_structure

(2) Active Directory kontekstis:
kogum puid, mis koosnevad
sidusa nimeruumi ühest või mitmest domeenist
= the highest level of organization within Active Directory,
a collection of trees that share a common global catalog, directory schema, logical structure and directory configuration
https://blog.quest.com/active-directory-forest-what-it-is-and-best-practices-for-managing-it/