Bjarni Jónsson

Bjarni Jónsson (February 15, 1920 – September 30, 2016) was an Icelandic mathematician and logician who made significant contributions to universal algebra, lattice theory, model theory, and set theory. He held the position of emeritus distinguished professor of mathematics at Vanderbilt University and served as the honorary editor in chief of *Algebra Universalis*. Jónsson earned his PhD in 1946 from the University of California, Berkeley, under the guidance of Alfred Tarski. His academic career also included affiliations with Brown University and the University of Minnesota, Minneapolis. In recognition of his work, he was elected a fellow of the American Mathematical Society in 2012. Jónsson's lemma, Jónsson algebras, ω-Jónsson functions, Jónsson cardinals, Jónsson terms, Jónsson–Tarski algebras, and Jónsson–Tarski duality are among the mathematical concepts and objects named in his honor, reflecting the profound impact of his research on these fields.