... This recently reintroduced area of research at the Observatory continues a tradition established at the Observatory by E.J. Opik , focusing on problems involving the origin and evolution of comets , their dynamical transfer from the Oort cloud and other reservoirs into short-period orbits , the interrelationship between comets and asteroids (particularly objects in Earth-crossing ... The first concerns the origin and evolution of the Oort cloud in the Galaxy. ...

... 17.1 New features . ... Pure procedures . ... A function NULL to nullify a pointer . ... Complete version of END INTERFACE Pure functions are functions without side effects, and elemental functions are pure functions with only scalar arguments and with scalar result. ... Elemental functions are pure functions with only scalar dummy arguments (not pointers or procedures) and with scalar result (not pointer). That a function is elemental can be indicated with the new ELEMENTAL prefix. ...