(no version information, might be only in CVS)
ps_arcn -- Draws an arc clockwise
Description
bool 
ps_arcn ( resource psdoc, float x, float y, float radius, float alpha, float beta )
   Draws a portion of a circle with at middle point at
   (x, y). The arc starts at an
   angle of alpha and ends at an angle of
   beta. It is drawn clockwise (use
   ps_arc() to draw counterclockwise). The subpath added to
   the current path starts on the arc at angle beta and
   ends on the arc at angle alpha.