... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... In the late 1970s, jets were discovered in megaparsec-long radio galaxies. ... This involved the first quantitative analysis of jet warping, bending and disruption in galactic halos. ... Hot spots are created where a jet finally crashes into the surrounding medium. ... I extended the so-called Twin Exhaust Model, using numerical simulations to show that hot gas can be ejected in three forms: jets, bubbles and clouds. ...

... 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. ...