My official homepages: (I) (II)
Publications -- a list of selected publications
Talks -- a list of selected talks
A New PreprintKristiansen, L.: On Subrecursive Representability of Irrational Numbers, Part II.
A Fairly New BookLeary, C. and Kristiansen, L.: A Friendly Introduction to Mathematical Logic.
The book is available from a number of internet bookstores.
Read a review from the Mathematical Association of America here.
.... and here is an another review of the book.
The book is listed as an Approved Textbook by AIM.
Recent Events in OsloProof, Computation, Complexity 2015
Symposium on the occasion of the retirements of Herman Ruge Jervell and Dag Normann
TeachingINF5840 - spring term 2017 (Computability Theory)
INF2080 - spring term 2017 (Logic and Computations)
MAT-INF3600 - autumn term 2016 (Mathematical Logic)
Barra's PhD thesis on small subrecursive classes is available here. The thesis also contains some stuff on ordinals and a problem of Skolem's.
MiscellaneousI am the owner of an offprint of "Ein Vollständigkeitsbeweis des zweiwertigen Aussagenkalküls" by Jan Lukasiewics. The cover is signed by the author with a dedication to Thoralf Skolem.
My Erdös number is less or equal to 3. (Check the details.)
My coauthors: Stål Aanderaa, James Avery, Amir Ben-Amram, Mathias Barra, Mark Burgess, Neil Jones, Christopher Leary, Robert (Bob) Lubarsky, Bedeho M.W. Mender, Jean-Yves Moyen, Karl-Heinz Niggl, Hans Kristian Ruud, Jan-Christoph Schlage-Puchta, Paul Voda, Andreas Weiermann.