In previous work investment and regional location have been analysed in terms of gaps or thresholds that should be closed or passed in order to produce operational results (growth, local development). <p> The topic is taken up again using a min-algebra which, at least to the knowledge of the author, has not yet be applied to (theoretical) spatial economics, though max-plus algebra has been used to tackle scheduling problems. <p> Examples of multiple gap situations will be given, together with their econometric implications; min-algebra will be defined, and examples of its applications worked out; topics for further research will be presented in conclusion.