The Integer Pre-Solver tab on the Options dialog box, pictured here:

is used to control several options for tailoring the operation of LINGO’s integer programming pre-solver. The integer pre-solver does a great deal of model reformulation, so that the final formulation passed to the branch-and-bound solver may be solved as fast as possible. The reformulated model is always mathematically equivalent to the original formulation, but it is structured in such a way that it is best suited for solution by the branch-and-bound integer programming algorithm.  The pre-solver also performs a number of heuristic techniques to find valid integer solutions before entering the branch-and-bound solver.