Electronic Journal of Differential Equations, Conference 06 (2001), pp. 203-214. Title: A mixed semilinear parabolic problem from combustion theory. Authors: Claudia Lederman (Univ. de Buenos Aires, Argentina) Juan Luis Vazquez (Univ. Autonoma de Madrid, Madrid, Spain) Noemi Wolanski (Univ. de Buenos Aires, Argentina) Abstract: We prove existence, uniqueness, and regularity of the solution to a mixed initial boundary-value problem. The equation is semilinear uniformly parabolic with principal part in divergence form, in a non-cylindrical space-time domain. Here we extend our results in \cite{LVWmix} to a more general domain. As in \cite{LVWmix}, we assume only mild regularity on the coefficients, on the non-cylindrical part of the lateral boundary (where the Dirichlet data are given), and on the Dirichlet data. This problem is of interest in combustion theory, where the non-cylindrical part of the lateral boundary may be considered as an approximation of a flame front. In particular, the results in this paper are used in \cite{LVWdf} to prove the uniqueness of a ``limit'' solution to the combustion problem in a two-phase situation. Published January 8, 2001. Math Subject Classifications: 35K20, 35K60, 80A25. Key Words: mixed parabolic problem; semilinear parabolic problem; non-cylindrical space-time domain; combustion.