This volume contains the papers selected for presentation at the 12th European Conference on Logics in Arti?cial Intelligence, JELIA 2010, which was held in Helsinki, Finland, during September 13-15, 2010. Logics provide a formal basis and key descriptive notation for the study and development of applications and systems in arti?cial intelligence (AI). With the depth and maturity of formalisms, methodologies, and systems today, such l- ics are increasingly important. The European Conference on Logics in Arti?cial Intelligence (or Journ' ees Europ' eennes sur la Logique en Intelligence Arti?cielle - JELIA) began back in 1988, as a workshop, in response to the need for a European forum for the discussion of emerging work in this ?eld. Since then, JELIA has been organized biennially, with English as the o?cial language, and with proceedings published in Springer's Lecture Notes in Arti?cial Intelligence series.In2010theconferencewasorganizedfor the?rsttime inScandinavia,f- lowing previous meetings mainly taking place in Central and Southern Europe.
The increasing interest in this forum, its international level with growing p- ticipation by researchersworldwide, and the overalltechnical quality has turned JELIA into a major biennial forum for the discussion of logic-based AI.