  A model glass with fast and slow processes is studied. The statics is simple
and the facilitated slow dynamics is exactly solvable. The main features of a
fragile glass take place: Kauzmann transition, Vogel-Fulcher law, Adam-Gibbs
relation and aging. The time evolution can be so slow that a quasi-equilibrium
occur at a time dependent effective temperature. The same effective temperature
is derived from the Fluctuation-Dissipation ratio, which supports the
applicability of out of equilibrium thermodynamics.
