  We define topological Landau-Ginzburg models on a world-sheet foam, that is,
on a collection of 2-dimensional surfaces whose boundaries are sewn together
along the edges of a graph. We use matrix factorizations in order to formulate
the boundary conditions at these edges and produce a formula for the
correlators. Finally, we present the gluing formulas, which correspond to
various ways in which the pieces of a world-sheet foam can be joined together.
