https://peertube.wtf/videos/watch/3e15ac36-54f5-4a0d-bd6f-dc4f49acbdcb This is the seventh in a series of talks about universal algebra and lattice theory. I introduce the notion of a complete lattice and (at long last) show that the congruences and subuniverses of an algebra form lattices. I also go over early results of Dedekind on congruence lattices of groups and Funayama and Nakayama on congruence lattices of lattices. The webpage for this series of talks can be found at https://aten.cool/2020ua.html. Sat, 22 Aug 2026 18:44:16 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://peertube.wtf https://peertube.wtf/lazy-static/avatars/45856119-df14-4b5f-bff8-4807ae2cfbd2.png https://peertube.wtf/videos/watch/3e15ac36-54f5-4a0d-bd6f-dc4f49acbdcb All rights reserved, unless otherwise specified in the terms specified at https://peertube.wtf/about and potential licenses granted by each content's rightholder.