codirection

Under the first of these, 5 collaborative research training fellowship projects were approved, on the following topics: stages of expansion of the railroads in Peru and their impact on its economy, under codirection of Heraclio Bonilla, Institute of Peruvian Sudies, Lima, and Marcello Carmagani, Luigi Einaudi Foundation, Turin Italy;...

It can be shown that the set of hyperbolic codirections consists of distinct pairs of oppositely-directed convex cones.