[For the entire collection see Zbl 0573.00014.]
A free Lagrange code for two-dimensional hydrodynamics, designed specifically to facilitate later generalisation to three-dimensional applications. The program sets up a network of triangular meshes filling a convex region within specified boundaries. The nodes of the network are Lagrangean in the region actually occupied by fluid, and Eulerian elsewhere. Fluid nodes are preserved throughout the subsequent hydrodynamic motion. The mesh lines connecting pairs of nodes are changed automatically whenever appropriate.