The 1999 Annual Conference of the European Association for Computer Science Logic, CSL'99, was held in Madrid, Spain, on September 20-25, 1999. CSL'99 was the 13th in a series of annual meetings, originally intended as Internat- nal Workshops on Computer Science Logic, and the 8th to be held as the - nual Conference of the EACSL. The conference was organized by the Computer Science Departments (DSIP and DACYA) at Universidad Complutense in M- rid...