BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Jennifer Hyndman (University of Northern British Columbia) DTSTART:20211130T200000Z DTEND:20211130T210000Z DTSTAMP:20260423T004730Z UID:PALS/19 DESCRIPTION:Title: A Reader's Guide to A Primer of Subquasivariety Lattices\nby Jennifer Hy ndman (University of Northern British Columbia) as part of PALS Panglobal Algebra and Logic Seminar\n\n\nAbstract\nBirkhoff and Mal'cev independentl y posed the problem: Describe all\nsubquasivariety lattices. Nurakunov in 2009 showed that there are many\nunreasonable subquasivariety lattices whe re unreasonable means there is\nno algorithm to determine if a particular finite lattice is a\nsublattice. This sugests refinements of the original question are needed.\n\nA subquasvariety lattice has a natural equaclosur e operator. Adaricheva\nand Gorbunov in 1989 defined an equaclosure operat or abstractly as\nhaving the properties that are known to hold in a natura l equaclosure\noperator.\n\nThe soon-to-be-published book\, A Primer of Qu asivariety Lattices by Kira\nAdaricheva\, Jennifer Hyndman\, JB Nation\, a nd Joy Nishida\, refines the\nabstract definition of equaclosure operator and provides some answers to\nthe refined question: When is a lattice with an equaclosure operator\nrepresentable by a subquasivariety lattice and t he natural equaclosure\noperator. This presentation explores some of this new approach.\n LOCATION:https://researchseminars.org/talk/PALS/19/ END:VEVENT END:VCALENDAR