We present broadband photometry in the optical, near infrared and sub-millimetre, and mid-infrared spectrophotometry of a selection of carbon stars with optically thin envelopes. ... Beside the emission features at 11.3 \mu m due to silicon carbide grains in the circumstellar environment, many of our mid-infrared spectra show an emission feature at 8.6 \mu m. All the observed spectral energy distributions exhibit a very large far-infrared flux excess. ...

... 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. ...