Bjarni Jónsson

Bjarni Jónsson (February 15, 1920 – September 30, 2016) was an Icelandic mathematician and logician working in universal algebra, lattice theory, model theory and set theory. He was emeritus distinguished professor of mathematics at Vanderbilt University and the honorary editor in chief of Algebra Universalis. He received his PhD in 1946 at UC Berkeley under supervision of Alfred Tarski.

In 1974 he was an invited speaker at the International Congress of Mathematicians in Vancouver where he spoke on Congruence varieties.

In 2012, he became a fellow of the American Mathematical Society.

Work Jónsson's lemma as well as several mathematical objects are named after him, among them Jónsson algebras, ω-Jónsson functions, Jónsson cardinals, Jónsson terms, Jónsson–Tarski algebras and Jónsson–Tarski duality.

Publications 1972: 1979: "Congruence varieties", pages 348 to 377 of Universal Algebra, second edition, by George Grätzer (appendix 3)