We model the spectral chanages of late oxygen-rich Miras observed in different pulsation phases. From a combination of variable near-IR spectra and UKIRT spectrophotometry of the 9.7 \mu m silicate dust emission feature in different phases we study the influence of the changing atmospherical circumstances on the conditions in the circumstellar dust shell. ... A comparision with the modelling results for another long period Mira U Ori is also provided. ...

... 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. ...